Marlins manager Dan Jennings said that recovery time for a position player is in the 9-10 month range, compared to 14-16 months for pitchers.
"It's unfortunate for him," Jennings said. "He's such a versatile guy and fit us in a lot of ways, with his veteran leadership."
Kelly can play pretty much anywhere, and he made the team out of Spring Training as a utility player who also would have been an emergency third catcher.
But Kelly appeared in just two games for Miami and had one at-bat. He fractured his right ring finger while fielding a ground ball at third base on April 12 against Tampa Bay. The next day he went on the disabled list.
In his recovery from the broken finger, he experienced discomfort in his throwing arm, and ended up having a significant ligament tear in his elbow.
"After he recovered from the broken finger that he had, he had some discomfort in his elbow-forearm region," Jennings said. "He ended up having to have the Tommy John."
Kelly debuted with the Pirates in 2007, and he was with the Tigers from 2009-14 before signing with Miami as a non-roster invitee to Spring Training.