Since the move, Upton's been showing arguably baseball's strongest arm in center. But his gasp-inducing fireballs have done more than just wow fans at Boston's Fenway Park, they change the complexion of the running game.
"Just the ability to hold up runners," Upton said, "and stop the extra bases that lead to runs."
"You always think about your strongest arm being in right field because of the throw to third base," manager Joe Maddon said. "My argument was always [that] you never know where the ball's going to be hit, but you need a strong arm."
Maddon can rest easy knowing that his center fielder owns only one of a pair of outfield cannons. Right fielder Delmon Young entered Wednesday's action ranked third in the Majors with 16 outfield assists behind Atlanta's Jeff Francoeur and Minnesota's Michael Cuddyer. Upton, who has found new life after an uncomfortable tour through three infield positions, can stay right where he is.
"I don't necessarily see [his arm] as being miscast," Maddon said. "I just think it's a nice bonus to have in that position right now."
Upton, who grew up idolizing infielders, now patterns his game after new heroes, Cincinnati's Ken Griffey Jr. and Atlanta's Andruw Jones, who are both known for their powerful throws.
But Upton's switch did require some adjustment. Infielders, Maddon said, tend to keep the full stroke of their throwing arm above the waist, as do catchers. The need to transfer and release as quickly as possible allows infielders to sacrifice power to make their throws.
Outfielders more typically drop their arms below their waste. Upton is beginning to do that -- with an infielder's speed.
"I think he has an outfielder's arm stroke," Maddon said. "I think what you're seeing -- I'd have to really break it down in slow-motion -- but I think what you're seeing is a quicker arm.
"He's learned how to get rid of the ball quicker. That's what you're seeing right now. He's always had the strong arm, from Day 1, when he went out there. The difference is, now how quickly he's getting rid of it."
Picking up the pieces: A day after the Rays surrendered an 8-1 lead, matching their season-high collapse of seven runs on June 5, Maddon said the bullpen was only part of the problem.
"I think [Tuesday was] an anomaly," he said. "They just came back on us. And again, it was not necessarily as much the bullpen. They weren't successful last night. But [starter Andy Sonnanstine] has got to get us deeper in that game with an [seven-run] lead."
The pitching staff had complemented a league-best scoring offense since Aug. 24 with the Majors' fifth-best ERA during that stretch.
"To their credit, our guys have been doing a nice job," Maddon said. "[Sonnanstine has] been good, the bullpen's been good. They beat us up last night."
Going west: After the conclusion of Wednesday's series at Fenway Park, the Rays will fly to Seattle, the only American League city they haven't yet visited. Only two weeks remain in the season.
"I think we do this around this time every year," Upton said. "But I love going there. Great city. Great stadium. And I think they're in the playoff race right now, so it should be fun."
Entering Wednesday's action, Seattle has fallen 6 1/2 games behind New York in the American League Wild Card race. After Seattle, the Rays will travel to Los Angeles, then they will come home to face the Red Sox and Yankees before finishing the season in Toronto.
Catching update: Backup catcher Josh Paul (back spasms) remained unavailable on Wednesday night, or else he would have served in his usual capacity as starter Edwin Jackson's personal backstop.
"He's getting better," Maddon said. "His back is still stiff. He's still available in an emergency situation. But it just doesn't seem prudent to push him at this time."
Emptying the cupboard: Maddon plans to use recent callup Jorge Velandia at shortstop on Thursday in Seattle to give middle infielders Josh Wilson and Brendan Harris a rest. Joel Guzman will likely get time against the Mariners, as well.
"If I can give [Wilson] a day off and [Harrison] a day off," Maddon said, "that'd probably do them both a lot of good."
Enforced discipline: The injury to Dioner Navarro's right wrist, which likely forced the Tampa Bay catcher to lay off low knucklers out of the zone from Tim Wakefield on Tuesday, might have led to his career-best 4-for-4 night.
"I've often said the slight injuries sometimes actually help some people, because you don't try to do too much," Maddon said. "Because you don't try to do too much. Apparently, that's what he was doing [Tuesday] night. He was making good swings, made good contact. But the thing for me that stood out was the fact that he was taking balls and swinging at strikes."
On the farm: On Tuesday night, the Triple-A Durham Bulls lost, 4-2, in Game 1 of the Governor's Cup Championship, the best-of-five final that determines the champion of the International League. Right-hander Jeff Niemann started for the Bulls against Richmond in Game 2 on Wednesday.
Also on Wednesday, the Double-A Montgomery Biscuits start their own best-of-five final, the Southern League Championship Series, against Huntsville. Right-hander Wade Davis got the start.
Finally, the Class A Columbus Catfish will take their 2-0 lead against West Virginia in the South Atlantic League Championship into Thursday night's Game 3. Righty Jeremy Hellickson will start.
Reunion: Rays broadcaster Joe Magrane will miss the entire Mariners series during the 20th anniversary reunion of the 1987 National League champion St. Louis Cardinals, for whom he started 26 games. Todd Kalas will replace Magrane in the booth. On deck: Right-hander Jason Hammel gets the start against Seattle's Jeff Weaver on Thursday at 10:05 p.m. ET.
Alex McPhillips is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.