Players are graded on a 20-80 scale for future tools -- 20-30 is well below average, 40 is below average, 50 is average, 60 is above average and 70-80 is well above average.
Check out all 30 team Top 20 lists and the Top 100 on Prospect Watch.
1. Casey Gillaspie, 1B
Preseason rank: None (2014 Draft)
Scouting grades: Hit: 60 | Power: 60 | Run: 20 | Arm: 40 | Field: 50 | Overall: 50
Conor Gillaspie starred at Wichita State before the Giants drafted him 37th overall in 2008, and he since has taken over as the White Sox third baseman. His brother Casey is not only following in his footsteps, but he went 17 spots higher in the 2014 Draft.
The younger Gillaspie established himself as one of the premier college power hitters in the class last summer in the Cape Cod League, and he kept on raking during his junior season. He has above-average pop from both sides of the plate, and he has improved his overall approach, barreling balls more consistently and showing excellent patience.
Relegated to first base because of a lack of speed, Gillaspie is a sure-handed fielder who makes the routine plays. It's his bat that got him drafted so highly, one that has been given the chance to be as good as slugging switch-hitters like Lance Berkman and Mark Teixeira.
2. Taylor Guerrieri, RHP
Preseason rank: 3
MLB Top 100 rank: NA (Preseason: 94)
Scouting grades: Fastball: 60 | Curveball: 60 | Changeup: 50 | Control: 55 | Overall: 50
Guerrieri began 2013 impressively, even earning a selection to the Futures Game, before an arm injury sidelined him in July and he eventually required Tommy John surgery.
When Guerrieri is healthy, he has the same kind of electric stuff that made him a first-round pick in 2011. He throws his fastball in the low-to mid 90s, down a tick from his high school days in South Carolina. Guerrieri's curveball has good depth, and it has the makings of becoming an out pitch. He made strides with his changeup, giving him three average-or-better offerings.
Guerrieri missed a large portion of the 2014 season recovering from surgery, finally returning in July, but he is still fairly young and should be able to make up for the lost time.
3. Hak-Ju Lee, SS
Preseason rank: 2
MLB Top 100 rank: NA (Preseason: 84)
Scouting grades: Hit 55 | Power: 30 | Run: 60 | Arm: 60 | Field: 60 | Overall: 50
Originally signed by the Cubs out of South Korea when he was 18, Lee was a key part of the package the Rays received in exchange for Matt Garza in 2011. A two-time Futures Game participant, Lee had lived up to expectations before torn ligaments in his left knee forced him to miss most of the 2013 season.
Lee's game is built around speed. More of a slap hitter, he slashes balls the other way and lets his speed do the work to get on base. He is a threat to steal, and he has swiped 30 bases three times in the Minor Leagues. Lee's speed helps him defensively as well. He has excellent range, soft hands and a strong arm. Lee has the potential to be a Gold Glove-caliber shortstop.
Lee returned in 2014 looking to make up for lost time. Even after what amounted to a lost year, he is on the cusp of reaching the Major Leagues.
4. Alex Colome, RHP
Preseason rank: 6
Scouting grades: Fastball: 65 | Curve: 50 | Cutter: 55 | Changeup: 50 | Control: 45 | Overall: 50
Jesus Colome spent parts of six seasons pitching out of the Rays' bullpen. His nephew, Alex, was on the brink of being able to do even more than that with Tampa Bay when a 50-game suspension for performance-enhancers at the start of the 2014 season put a cloud over his future. Colome did bounce back from that to make it back up to the big leagues in late May.
Colome has all the weapons to start, beginning with a fastball that can touch 95-96 mph. He throws a hard cutter-like slider that is an out pitch at times, and his changeup shows flashes of being above average as well. Colome struggles with the consistency of his secondary stuff, but he has the ceiling of having three above-average Major League offerings if it can all come together. Staying healthy -- Colome has missed considerable time in each of the past two seasons -- would help him get the mound development time he needs.
Now past his suspension, if Colome can stay healthy, he might be able to continue as a starter. If not, he could follow his uncle's path to the bullpen.
5. Enny Romero, LHP
Preseason rank: 5
Scouting grades: Fastball: 65 | Curve: 50 | Changeup: 45 | Control: 45 | Overall: 50
As far as electric left arms go, Romero belongs on any short list among prospects. Whether that arm can stay in a rotation or is destined for the bullpen remains to be seen.
Romero has as dominant a fastball from the left side as just about any young arm in the Minor Leagues. As overpowering as he can be, though, he doesn't miss as many bats as you would think. That's largely because it's Romero's secondary stuff that will determine his long-term role. He has become more aware of the need to mix in his curve, improve his changeup and his command to get big league hitters out. Romero has the chance to remain a starting pitcher.
Romero will get every chance to do just that, but knowing he has the power stuff to succeed as a reliever is a good fallback.
6. Nick Ciuffo, C
Preseason rank: 7
Scouting grades: Hit: 50 | Power: 55 | Run: 30 | Arm: 60 | Field: 55 | Overall: 50
At No. 21 overall, Ciuffo was the second catcher selected in the 2013 Draft, behind only Pittsburgh's Reese McGuire. The South Carolina prepster has a good understanding of the game, and he adjusted well to the Minor Leagues.
At the plate, Ciuffo has an up-the-middle approach, and he produces good bat speed. Big and strong, he has solid power potential.
Behind the plate, Ciuffo isn't afraid to take charge and be a leader. He has a strong arm and has improved his receiving skills, though they still need some work. Ciuffo is a long way from the big leagues, but he has the tools to become a Major Leaguer in time.
7. Ryan Brett, 2B
Preseason rank: 9
Scouting grades: Hit: 50 | Power: 30 | Run: 70 | Arm: 45 | Field: 50 | Overall: 50
A 50-game suspension now firmly in his rearview mirror, Brett is building off of a solid 2013 season that saw him finish the year in Double-A. He is close to knocking on the big league door.
Though small in stature, it would be a mistake to underestimate Brett due to size. He has a compact body with strength particularly in his wrists and forearms. With an advanced approach at the plate, a knack for making consistent contact and excellent speed, Brett has the chance to be a true top-of-the-order catalyst. His defense, once very crude, has come a long way and he profiles well at second.
Brett is known for his hustle and hard-nosed style of play. He has the chance to be an everyday second baseman who can set the table well for the run producers in a big league lineup.
8. Cameron Varga, LHP
Preseason rank: None (2014 Draft)
Scouting grades: Fastball: 60 | Curveball: 60 | Changeup: 45 | Control: 50 | Overall: 50
The Rays have never shied away from trying to draft and develop high-ceilinged pitchers, so it was no surprise they took Varga from the Cincinnati high school ranks. They went slightly over pick value to lure him away from North Carolina.
Varga has a terrific pitcher's build at 6-foot-3 and 205 pounds. As a onetime shortstop prospect, he's athletic as well. Varga delivers 90-95 mph fastballs with good life and an easy delivery, making his heater appear to jump on hitters at the plate. He also adds some power to his curveball that could be a plus pitch in the future, and he shows some aptitude for throwing a changeup as well.
Varga erased concerns about his health this spring after he had biceps tendinitis during the summer showcase season in 2013. There's some upside here, though it may take some time for Varga to reach it.
9. Ryne Stanek, RHP
Preseason rank: 12
Scouting grades: Fastball: 65 | Curve: 50 | Slider: 55 | Changeup: 40 | Control: 45 | Overall: 45
Based on raw stuff, Stanek shouldn't have even been available to Tampa Bay at No. 29 in the 2013 Draft. Thanks to offseason hip surgery, the club had to wait to see if he can be a Draft steal, though he returned in May, and he earned a promotion in July.
The Arkansas right-hander has a huge arm, one that fires well-above-average fastballs, a pair of breaking balls and a changeup. At some point, he might combine the breaking balls, with his slider a better option than his curve and the changeup being a clear fourth option. There are delivery issues to iron out, and the Rays are hopeful that the reps he got in rehab will help smooth some of them out.
Stanek didn't throw a competitive pitch until May. Tampa Bay thinks he can start, but the fact that his big arm would play well in the bullpen doesn't hurt.
10. Mikie Mahtook, OF
Preseason rank: 15
Scouting grades: Hit: 45 | Power: 45 | Run: 50 | Arm: 50 | Field: 50 | Overall: 45
The Rays went on a college hitter streak in the first round of the Draft, first taking Mahtook in 2011, then Richie Shaffer the following year. While neither has blown the roof off, there's hope that both will contribute in St. Petersburg soon.
Mahtook, the former LSU standout, is the type of player who has the chance to be good at everything, even if he's not great at anything. At his best, he has average tools across the board. Though he's an average hitter and has average power, he started to produce more consistently with the bat in 2014. If Mahtook can reach the upper levels of those grades, he has the chance to be a valuable big leaguer.
That might not be as a starter in one spot, though seeing Mahtook playing right field every day isn't out of the question. A career as a productive fourth outfielder might seem more realistic at this point.
11. Andrew Toles, OF
Preseason rank: 4
Scouting grades: Hit: 55 | Power: 45 | Run: 70 | Arm: 45 | Field: 55 | Overall: 45
Toles, a toolsy and athletic outfielder, seemed primed to jump on the major prospect map following a breakout first full season in the Rays' system. His future, however, is in question after first being pulled from a game for not hustling and then being put on the temporary inactive list.
When on the field, Toles is a dynamic top-of-the-order center fielder who has the chance to impact the game, particularly with his speed on both sides of the ball. He needs to improve his plate discipline, but he has shown an ability to hit for average and he has enough bat speed to hit for some power down the road. Toles' plus speed makes him a major basestealing threat, and it gives him outstanding range in center.
Toles will have to show he can mature and put the questions about his makeup behind him if he wants to continue moving up the ladder. If he can do that, there will be reason once again to be excited about his future.
12. Blake Snell, LHP
Preseason rank: 10
Scouting grades: Fastball: 60 | Slider: 55 | Changeup: 50 | Control: 45 | Overall: 50
Being projectable and left-handed is an outstanding combination. Put that together with the Rays' ability to develop young pitching, and there's still reason to be excited about Snell's future.
Snell's full-season debut in 2013 was disappointing in terms of executing pitches and commanding the baseball, but he still has a high ceiling and he started showing progress with a midseason promotion in '14. He has good life on his fastball, a true slider that flashes plus and a changeup that also can be an out pitch at times. Snell will need to find a greater level of consistency and show he can find the strike zone with more regularity as he moves forward. Mental and physical maturity should help on both fronts.
Tampa Bay knows how to be patient with young arms, and the club will do just that with Snell. The end result could still be a solid big league starter.
13. Justin O'Conner, C
Preseason rank: None
Scouting Grades: Hit: 40 | Power: 50 | Run: 30 | Arm: 70 | Field: 55 | Overall: 45
It's taken a while for O'Conner to get going, but it looks like this former first-round pick is now headed in the right direction.
O'Conner spent three summers in short-season ball before finally graduating to a full-season level in 2013. There, he started to show some of the extra-base ability the Rays knew he'd always possessed. O'Conner needs to continue to refine his approach, but he's much improved at tapping into his considerable raw power.
Behind the plate, O'Conner has one of the best arms in the Minors, one that allows him to control an opponent's running game. He's still learning the plate, but he has the chance to be an elite defender.
It all comes down to O'Conner's bat. If it continues to develop, he has the chance to be an everyday backstop at the highest level.
14. Nate Karns, RHP
Preseason rank: 8
Scouting grades: Fastball: 65 | Curveball: 55 | Changeup: 45 | Control: 50 | Overall: 45
A torn labrum limited Karns at the start of his professional career, but he put those problems behind him in 2012. He built on that success in 2013 and made three starts in the Major Leagues before being acquired by Tampa Bay in February '14 for catcher Jose Lobaton.
When he's on, Karns' fastball sits around 93 mph, with good sinking action. He pairs it with a hard curveball, which is a legitimate swing-and-miss offering. Karns has made strides with his changeup in recent years, but it still isn't as advanced as his other two pitches. His command had been improving as he has gotten further removed from his injury, but he had trouble locating the strike zone in his first season with the Rays.
Karns didn't excel in his first go-round in the Nationals' rotation, then he struggled in Triple-A with Tampa Bay, leading some to wonder if a switch to the bullpen might be in the works.
15. Riley Unroe, SS
Preseason rank: 17
Scouting grades: Hit: 50 | Power: 35 | Run: 60 | Arm: 55 | Field: 55 | Overall: 45
Sons of former Major Leaguers often have an advanced aptitude for the game. So far, the Rays have been pleased with their 2013 draftee, the son of Tim Unroe, and his approach.
While Unroe is younger than most of the high school draftees from the 2013 Draft, he doesn't play like it. He has a good feel for hitting, showing good on-base skills right away from both sides of the plate. Unroe can drive the ball, though power isn't expected to be that big a part of his game. Unroe runs well, and while he still has a lot to learn, he has the chance to stay at shortstop long-term.
There's plenty of time for Unroe to develop, but his combination of tools and aptitude should excite those pondering his future.
16. Mike Montgomery, LHP
Preseason rank: 19
Scouting grades: Fastball: 55 | Curve: 45 | Slider: 50 | Changeup: 55 | Control: 40 | Overall: 45
On prospect radars for some time now, a strong Arizona Fall League showing has the Rays hopeful that the lefty they got from the Royals in the James Shields deal might finally be ready to cash in on his potential.
Montgomery has been inconsistent during his professional career game, with his stuff backing up following an injury while with Kansas City. In the AFL, he started throwing in the mid-90s in shorter relief stints, closer to the velocity that he used to reach as a starter. His changeup is still a very good pitch. Montgomery worked on his breaking ball more in Arizona, which has been slower to develop, but was looking better than it has in a few seasons.
Montgomery will continue to work on execution of pitches, with the hopes that the AFL wasn't a mirage in terms of his stuff bouncing back.
17. Tim Beckham, SS/2B
Preseason rank: 14
Scouting grades: Hit: 45 | Power: 40 | Run: 50 | Arm: 55 | Field: 45 | Overall: 45
Beckham's opportunity to live up to the hype of a No. 1 overall pick may be past, but he still has the chance to be a very valuable big league contributor.
That might have happened in 2014 until Beckham tore his UCL working out in December, which will cause him to miss a good chunk of the season. Once healthy, he still has the overall tools to potentially exceed his grades, though his production to date might say otherwise. Beckham came on in the second half of the 2013 season, starting to show some more signs of offensive life, with some thinking he might be a late-bloomer type.
Beckham may never be the everyday shortstop some envisioned, but he could be an offensive-minded utilityman in an organization that values positional flexibility.
18. Grayson Garvin, LHP
Preseason rank: 20
Scouting grades: Fastball: 50 | Slider: 50 | Changeup: 55 | Control: 50 | Overall: 45
When the Rays took Garvin out of Vanderbilt in 2011, the thinking was he'd be a quick-moving college lefty, a hope that was dashed by elbow surgery in '12.
Garvin did come back in 2013, and he threw fairly well, even picking up some extra innings in the Arizona Fall League. When he's 100 percent healthy, he's the typical pitchability lefty with average stuff across the board. The one exception to that might be Garvin's changeup, which is often above average. He mixes his pitches well, throws strikes and uses his 6-foot-6 frame to throw downhill.
While much of his first two seasons were lost, Garvin looks poised to return to fulfill his fast-rising lefty status. If he can stay away from the disabled list, he fits the profile of a middle- to back-end-of-the-rotation starter at the big league level.
19. Kean Wong, LHP
Preseason rank: None (2014 Draft)
Scouting grades: Hit: 50 | Power: 35 | Run: 45 | Arm: 50 | Field: 45 | Overall: 45
The younger brother of Cardinals second baseman Kolten Wong, Kean has already shown an ability to make a name for himself with his bat.
Unlike his brother, who played for the University of Hawaii, Kean signed out of high school rather than going on to play for the Rainbows. In his brief time in the Rays' organization, he's shown a knack for making consistent and hard contact with an advanced approach at the plate. Wong has a quick swing from the left side, and he should also bring a little power to the plate as he progresses. Compact and strong, Wong is fairly physically mature and doesn't run quite as well as his brother does.
While Wong's defensive skills grade out as adequate, he does get very high marks for his makeup, meaning he will maximize his abilities on both sides of the ball. Right now, he profiles as an intriguing offensive-minded second baseman of the future.
20. Jeff Ames, RHP
Preseason rank: None 16
Scouting grades: Fastball: 55 | Slider: 50 | Changeup: 45 | Control: 50 | Overall: 45
Remember all of those extra picks Tampa Bay had in the 2011 Draft? Ames could end up being the best of the seven sandwich picks.
The tall right-hander from the Pacific Northwest is still developing what could be a very effective three-pitch mix, with a fastball that sits in the low 90s, a slider that can be nasty at times and a changeup that flashes average. He has fairly good command of all three, and there's room for improvement on that front. Ames' best quality, his competitiveness, can also be his downfall as he still needs to learn how to pace himself.
The Rays don't want him to lose that edge, thinking it's a lot easier to cool off hot water. If he can learn to conserve, he could be a starting-pitching candidate in the future, though trips to the disabled list in 2014 cut into his development time.