Moss wasn't feeling well Friday night, but went 2-for-4 with a home run and an outfield assist against the Rays. He was still feeling ill when he arrived at Fenway Park on Saturday and was sent to the hospital as a precautionary move. Once there, the decision was made to perform the surgery.
"The medical team felt that there was a possibility, rather than just an abdominal flu, that this was a possibility, so we took him over there right before the game, which was probably a good idea," Boston manager Terry Francona said after Saturday night's 12-4 victory over Tampa Bay.
"We were trying to be safe rather than sorry, and he's having it removed right now. That makes [Friday] night even more unbelievable. He said he didn't feel good, swung the bat good, threw the ball well. I'm sure he was feeling it."
Moss was out of surgery late Saturday and doing well, according to the club.
Francona said the club might not make a roster move before Sunday afternoon's game against the Rays.
"We may elect to try to get through [Sunday] and see how we're situated," he said. "That's how we're going to look at it.
"We don't want to rush to make a move and then have somebody have to leave the game, or someone be sore and have to make another move."
Mike Shalin is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.