While the Red Sox had always felt Kelly's biggest upside was on the mound, they were pleased that the 20-year-old right-hander came to that same conclusion on his own.
"We wanted him to do what to do what was in his heart," said Red Sox general manager Theo Epstein. "You force someone to do something, in a game as difficult as baseball, you're probably not going to get good results."
Epstein, director of player development Mike Hazen and Minor League instructor Gary DiSarcina flew to Florida to meet with Kelly at the beginning of last week. While the sides exchanged ideas, Epstein said that the organization left the final decision in Kelly's hands.
"It's something that the organization is really pleased about," said Epstein. "Casey feels great about his decision. He called me a couple days ago, he spent a lot of time thinking about it, and we spent a lot of time talking to him about it. Ultimately, he did a lot of soul searching and decided that pitching was what he wanted to do, and he sees himself as a pitcher going forward."
Kelly, who has a conference call scheduled with the media for Tuesday, will participate in Boston's rookie development program in January. He will get an invitation to Major League Spring Training camp, but the club hasn't yet decided which Minor League affiliate the right-hander will start at in 2010.
"We feel like he has a chance to pitch in the upper Minors and he's talented," said Epstein. "He could, if everything breaks his way, force his way on to the Major League radar screen sometime in the next year or two. We think he'll benefit from being in the big league atmosphere and working with [pitching coach] John Farrell, from seeing how Jon Lester and Josh Beckett, among others, go about their business, as he completes this transition of being a full-time pitcher."
The first time Kelly had to make a decision was when the Red Sox drafted him out of high school. At that time, rather than signing with Boston, he could have taken a football scholarship at Tennessee. He chose baseball, and now Kelly will pursue the path of becoming a starting pitcher.
"He's got three pitches that all project as plus -- actually four, if you count the two-seam and four-seam fastball, power curveball [and] changeup," Epstein said. "He could at some point add a slider when appropriate, but right now, [he has] three pitches. He's got command well beyond his experience. He's got great feel, he's got the ability to manipulate the ball both ways, and on both sides of the plate.
"He's just advanced. You do get the feel, just watching him at times, when he's locked in, that he almost looks like a big leaguer out there, even though he's 19, or was 19, and is going to pitch at 20 this year. Even though he hasn't pitched much, he has advanced feel, and there's a lot for him to work on. He's already pretty good, his future's bright."
Splitting his season between Class A affiliates Greenville and Salem, Kelly was 7-5 with a 2.08 ERA in 19 starts in 2009. At the plate, he hit. 136 with three homers and 16 RBIs in 162 at-bats.
"I think he sees he's relatively close to the big leagues, certainly for his age, and has a chance to really make an impact in the organization," Epstein said. "I think he would have had a future as a big leaguer as a position player, too -- he's very gifted."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.