Sweeney fractured the knuckle of his pinkie finger on his left hand in the eighth inning of Monday's 7-3 win over the Tigers. He had a screw inserted into his throwing hand on Tuesday and will be out for at least six weeks.
With just over two months remaining in the regular season, Sweeney will be hard pressed to return in time to play.
"I guess it just depends on how the rehab goes and how the screw heals with my bone. I think that six weeks is rushing it back," said the outfielder, on the disabled list for the third time this season. "But I think it could possibly heal before the season is over. It's just the factor of hitting a 95-mph fastball and taking that jolt."
Before Wednesday's game against Detroit, Sweeney said he's learned from the incident.
"Obviously it's the heat of the moment and trust me, I regret it," he said. "I let my teammates down, and that's the biggest thing -- not being there for your team and being able to be out on the field. It's a tough thing to swallow. I've been sick to my stomach and disgusted with what happened."
He also dismissed the notion that he injured himself on purpose to prevent a trade from the Red Sox. The injury occurred one day before Tuesday's non-waiver Trade Deadline.
"I didn't intentionally do it so I wouldn't get traded," Sweeney said. "That had nothing to do with it. It was bad timing. It was a freak accident I guess. That didn't even cross my mind. I didn't even really think about that until somebody said something."
Sweeney missed six games with a concussion in late May before going on the DL June 17 with a toe injury that cost him 15 games. Now, he has a new pair of boxing gloves courtesy of Wednesday starter Aaron Cook.
"It's pretty funny that he's pitching today and he has time to think about that," Sweeney said. "I can tell you I won't be punching anything."