BOSTON — Daisuke Matsuzaka could be headed to the disabled list after an MRI taken Saturday indicated the Red Sox right-hander is suffering from shoulder weakness.

"Dice has been examined. He was MRI'd," said manager Terry Francona after Saturday night's victory over the Braves. "We were fortunate enough to get that done.

"There's no structural damage, which is really good. We don't have anything official to announce because we really need to let this thing settle down. I will say, I don't think it's any surprise, there's some weakness that we're going to have to fix. By that, it's going to have to be addressed, but there is no official announcement tonight.

"Spent some time, obviously, talking to Dice, to [general manager Theo Epstein], to [pitching coach] John Farrell, and spent a few minutes after the game with [team physician Dr. Thomas Gill] getting an update. We have Monday off and we'll have an official [announcement] from Tom and Theo and, I guess, me."

Matsuzaka's day to pitch would have been Thursday, but that's also the day John Smoltz is scheduled to make his return from rehab. The Sox had already announced before Saturday night's game that Matsuzaka would skip at least one start.

"We've been fighting this all year," Francona said. "It's been hard, and I know that I keep coming back to the [preseason World Baseball Classic, in which Matsuzaka was named MVP after pitching Japan to the championship], and that's probably not a real popular thing in baseball to say that, but he didn't really have a chance to get a foundation [because he skipped spring training and went right into competitive pitching].

"You're ramped up to try to get people out probably before their bodies or their arms are ready to do that and I think we paid the price for that," he continued. "We've been playing catch up, we did what we thought was right to shut him down earlier, I think we all see that it's not really getting strong or better. It's been a struggle so we're trying to address that."

roblee@projo.com