The eight players who will be cut are: outfielders Chris Richard, John Rodriguez and Jon Weber; infielder Andy Cannizaro; catchers Mike DiFelice and Josh Paul; and pitchers Scott Munter and Grant Balfour.
None of the moves will be official until after Saturday's final Spring Training game in Sarasota, Fla., in case any injuries occur. At that time, the players' destinations will become known.
Friday's activity unofficially put the Rays' roster at 29 players, and they must get down to 25 by 3 p.m. ET on Sunday.
The Rays' pitching staff now appears decided, with a starting rotation of James Shields, Matt Garza, Andy Sonnanstine, Edwin Jackson and Jason Hammel and a bullpen that includes Troy Percival, Al Reyes, Dan Wheeler, Gary Glover, Trever Miller, Scott Dohmann and J.P. Howell.
Balfour, who lost out in his battle with Dohmann to claim a relief spot, is out of options, which means he will have to clear waivers to remain in the organization.
"I thought I threw the ball pretty good," said Balfour, who went 1-0 with a 3.00 ERA in 10 games this spring. "But at the end of the day, it makes no difference, so I'm outta here. That's the way it goes.
"... I could have given up no runs and still not made the team. I don't know. It was disappointing. I put up a fight and that's the way it goes. I wish them the best of luck."
Weber smiled through the disappointment.
"It was a blast," Weber said. "I had an awesome time, a lot of fun."
Haynes, 28, made his Major League debut in 2007 with the Angels, hitting .267 in 40 games; his contract was purchased May 28 from Triple-A Salt Lake City and he remained in the Major Leagues the remainder of the season.
"Nathan's a guy that we like," said Andrew Friedman, the Rays' executive vice president of baseball operations. "[Manager] Joe [Maddon] has some history with him. We like his ability to play all three of the outfield spots, how he handles the bat and his foot speed."
This spring, Haynes hit .265 (9-for-34) with four stolen bases in 19 Cactus League games for the Angels.
He bats and fields left-handed, and is a career .281 hitter with 254 stolen bases over parts of 11 Minor League seasons with the A's, Giants and Angels organizations. He was the 32nd overall player selected in the 1997 First-Year Player Draft by the Athletics.
Baldelli missed most of the 2007 season with hamstring problems stemming from an abnormality (mitochondrial disorder) that has kept him in a constant state of fatigue. Earlier in the spring, Friedman said that the Rays are not likely to renew Baldelli's option for the 2009 season, which they must do by April 1.
Willy Aybar's status could affect whether infielders Joel Guzman, Elliot Johnson and Eric Hinske (who also plays outfield) make the team. Friedman reported that Aybar (left hamstring) continues to progress -- he went 1-for-2 with a home run and a walk in a Minor League game Friday.
"He came out feeling good," said Friedman, who noted the club is still concerned about how Aybar's hamstrings will react to the cold weather in Baltimore.
If healthy, Aybar will likely be the team's starting third baseman.
Friedman added that left-hander Kurt Birkins (left elbow) and right-hander Chad Orvella (right shoulder) will likely begin the season on the disabled list.
Meanwhile, Friedman believes that right-hander Juan Salas will show before the team leaves for Baltimore. The relief candidate has been stuck in the Dominican Republic with visa problems for all of Spring Training.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.