NEW YORK -- The Red Sox had multiple pieces of good news on the injury front on Saturday.

Righty Andrew Bailey, who has yet to throw a pitch for his new team, had his second successful batting practice session of the week and has been cleared to start a Minor League rehab assignment.

Bailey -- who underwent right thumb surgery the day before the regular season started -- is likely to pitch in a Gulf Coast League game on Monday in Fort Myers, Fla. He'll probably move up to an affiliate shortly thereafter.

"We're just going to go one at a time for right now," said Bailey. "I'm sure the process of getting back is throwing a back to back and that kind of stuff. A couple and then back to back and maybe one more and we'll be good to go. It just kind of depends on where the teams are and that kind of stuff."

Considering the way Alfredo Aceves has flourished in the closer's role, Bailey isn't preoccupied with what role he will pitch in when he returns.

"Yeah, I don't really care," said Bailey. "I just want to pitch. At this point, I've missed enough time to know that, 'Hey, he's done a [heck] of a job this year and the bullpen has been great all year,' so for me, I just want to find my role -- whatever that is -- and finish the year and get to the playoffs. That's what our goal is and I've said that from Day 1. Even in Oakland, I didn't care what I'm doing as long as I'm pitching good in the big leagues and we're winning. That's all I care about."

Meanwhile, starting pitcher Daisuke Matsuzaka, out since July 3 with a neck injury, will open his rehab assignment with Triple-A Pawtucket on Monday.

"We have a plan for him to pitch in a rehab assignment starting in Pawtucket on Monday," said Red Sox manager Bobby Valentine. "That would be a pitch-limited session, but he's feeling good. Right now, he's throwing the ball -- the last session he had in the outfield and on the mound was his best session so far since Spring Training."

Crawford gets medically mandated day off

NEW YORK -- Fresh off a home run on Friday night, his first since being activated, Carl Crawford found himself on manager Bobby Valentine's bench on Saturday, despite a .319 career average against Yankees starter CC Sabathia.

Valentine said that the reason Crawford wasn't in the lineup was because of a plan mandated by the medical staff that the left fielder should play no more than four games in a row.

In fact, Valentine was candid about the fact he blew off this plan earlier this month, when he wound up playing Crawford six days in a row, from July 16-21, after he came off the disabled list.

"Actually, I did a manager no-no thing and went against what I was told to do. Never to be done again," Valentine said. "They told me before that game that he wasn't playing, and I kind of did the old veto power. 'Who says he's not playing?' And I played him."

Crawford has a strained UCL in his left elbow and is all but certain to undergo Tommy John ligament transfer surgery before the start of the 2013 season.

The Red Sox actually had a day off Thursday, which meant Valentine had the leeway to play Crawford on Saturday. But the Red Sox are facing three straight righties beginning on Sunday, so Valentine felt it would be more beneficial to have him in the lineup for those games.

"My understanding is that I got today off, and I know the medical people want me to get rest," Crawford said. "I'm not really sure what's the program on it. I guess that's the way it is right now. I came here ready to play, like I always do. I found out this morning I wasn't playing. That's it, pretty much. Could I play? Yeah, I could play today. Like I say, they're following that method right there. I'm just going along with the way things are."

It is a unique situation for everyone involved -- particularly Valentine.

"I'd like to have Carl every day," said Valentine. "I'd like to have all my good players every day, but I understand the situation better now than I did then."

Crawford said he didn't hear about the four-day plan until Saturday morning.

"Oh, I just found out about that today," Crawford said. "You know, like I say, he texted me this morning and told me that. That's the plan they came up with. I'm just going to follow that."

Being the competitor he is, Crawford didn't seem thrilled about the timing of this particular day off.

"I don't want to run from guys," Crawford said. "It feels more like I'm hiding from somebody. Not playing against someone [like Sabathia] is more embarrassing than anything. My body is fine right now. If I play five, six games, or four games, and need a day off, that's the system. We'll see how long that system holds up, you know?"

Though Crawford knows he could blow out his elbow at any time, he said it's not on his mind when he takes the field.

"Once I get ready for the game, I'm ready for the game," Crawford said." I think the medical staff knew that at some point early on, they wanted to give me the day off and I got that day off. I guess, you know, they've talked, and said this is probably best for me and just have to go with whatever plan they come up with."

The Red Sox entered Saturday's game 11 1/2 games back in the American League East, and 5 1/2 behind in the Wild Card standings. If they fall any further back, it might be logical for Crawford to have his surgery well before the season ends so he can give himself a chance to be ready for the start of '13.

"That would be the smart thing to do, if we're out of it," Crawford said. "You definitely want to try to take care of it as soon as possible. Like I say, we just have to wait and see. Right now, that's why I tried to get back so quick and help the team. If we're still in it, I want to do that. If not, we probably have to look into it."

Setback for Atchison?

NEW YORK -- Not only did reliever Scott Atchison get hit hard (one inning, three hits, three runs) during the opener of his Minor League rehab assignment on Friday, but he didn't appear to feel healthy.

Atchison has been on the disabled list since July 14 with tightness in his right forearm.

"Atch threw last night and didn't have great results and didn't feel so great this morning when he woke up, so I don't think there's anything imminent with him on the Major League roster," said Red Sox manager Bobby Valentine. "Physically. I'll bet he gets some tests, probably an MRI."

Atchison has been one of Boston's best relievers this season, going 2-1 with a 1.76 ERA.