BOSTON -- The Red Sox had a new look to their lineup on Monday afternoon, as Daniel Nava batted leadoff for the first time this season and Mike Aviles occupied the No. 9 spot.

This wasn't a demotion for Aviles, but more of a break. Valentine expects to restore Aviles to leadoff on Wednesday.

"He does a great job and I think once in a while, being he's playing every day, I think he just needs a little breather, and today he's in the ninth spot," Valentine said. "Two days from now, he'll be in the leadoff spot, probably."

Aviles is an aggressive hitter, so he's not the prototypical leadoff man.

"There's no way of measuring it," Valentine said. "I'd love to have traditional on-base guys in front of the guys who hit home runs and everything. When you're making do with what you have, I don't mind a guy who can do some damage up there. And you know, Mike has done a great job."

Valentine continues to enjoy the contributions of Nava.

"Nava has played so well," Valentine said. "His at-bats are calm and deep and he might have the best on-base percentage on our team for this short period, whatever that's worth. Hopefully he'll get on in front of the big spots. I was reluctant to do it earlier, only because he was getting his feet wet at the Major League level and I didn't want to get him in over his head. It seems like he's settled in nicely."

Like everyone else, Valentine knew that Nava had hit a grand slam in his first Major League at-bat back in 2010. But he didn't know a whole lot else, mainly because Nava wasn't even on the Spring Training roster this season.

"Well, he wasn't even on my radar when I got to Spring Training or even during the winter time, so I'm pleasantly, extremely surprised and happy," Valentine said. "[He's a] great guy."

Pedroia exits with jammed right thumb

BOSTON -- Second baseman Dustin Pedroia had to leave Monday's 7-4 win over the Tigers in the top of the sixth inning with a jammed right thumb and will undergo further tests.

After making a diving stop to rob Danny Worth of a hit to end the fifth inning, Pedroia came to the dugout and was looked at by the training staff.

It sounds as if Pedroia might have jammed his thumb before the dive, and perhaps that play aggravated it further.

"I was just wondering what happened, because I was going to wear him out," said shortstop Mike Aviles. "In all honesty, I was like, 'You just dove and you came out of the game?' I thought he came out of the game because of the dive. In all honesty, I guess his thumb was jammed pretty good. He got a couple of innings off and I'm pretty sure he's going to be in there tomorrow. There's not that many people that can stop him from getting back in that lineup."

However, manager Bobby Valentine indicated that he doesn't expect to have Pedroia for Tuesday's game, when the Red Sox face Tigers ace Justin Verlander.

"Right now, I don't think he'll play tomorrow," Valentine said.

When Boston took the field for the sixth, Nick Punto replaced Pedroia at second base.

Pedroia certainly finished his work day with a flourish.

"He plays a little up the middle against righties, which is pretty normal," Aviles said. "And for where he had to go to stop that ball and to make a good throw, and he was dealing with that jammed thumb before that, I think that was pretty impressive."

Pedroia went 1-for-3 on Monday and is hitting .295 on the season with five homers and 21 RBIs. The invaluable Pedroia has started all 48 games the Red Sox have played this season.

Sweeney notches three hits in return to lineup

BOSTON -- The Red Sox's injury-depleted outfield got a reinforcement on Monday, as Ryan Sweeney was activated from the seven-day disabled list and started in center field in a 7-4 win over the Tigers.

Sweeney had been out with a concussion, but he passed all the requisite tests to be activated on the first day he was eligible to return.

And once Sweeney stepped into the batters' box, he proved he was fine. Sweeney belted a double off the wall in center in his first at-bat and finished the game 3-for-4 to raise his average to .325.

"I got right back into it," said Sweeney. "My body is a little tired right now just because I haven't played in a week, but other than that, everything feels great. I wasn't trying to do too much up there."

Sweeney thinks that the new seven-day DL that has been instituted specifically for concussions is a good thing.

"I've never had a head injury, but I think it's a good idea, especially for guys like me who maybe had a mild one and don't need to go on the 15-day DL, that you can maybe have seven days to get back to where you were before and not feeling a little bit goofy, so you can get that seven days to get back to where you need to be and to get back in the lineup," said Sweeney.

To make room for Sweeney on the roster, the Red Sox optioned Che-Hsuan Lin to Triple-A Pawtucket.

Sweeney has also played well defensively, rotating between center and right.

It appears Sweeney will get more time in center now that Adrian Gonzalez is getting a lot of his playing time in right field.

But manager Bobby Valentine expects Sweeney will play right on Tuesday, as Kevin Youkilis or Will Middlebrooks is likely to get a day off against Detroit ace Justin Verlander.

Darnell McDonald should also return to the mix soon, as he played his third rehab game for Triple-A Pawtucket on Monday.

Crawford starts swinging; Ellsbury now throwing

BOSTON -- Carl Crawford and Jacoby Ellsbury are under the radar right now, but they continue to take steps toward a return to action, which, in both cases, probably won't be until July.

Crawford (sprained UCL in left elbow) has progressed to taking 40-50 swings off the tee, and he hasn't felt any ill effects. Ellsbury has started playing catch, marking his first baseball activity of any kind since separating his right shoulder on April 13.

Meanwhile, closer Andrew Bailey, who is recovering from right thumb surgery, will start throwing at 90 feet by the end of this week. Bailey is doing his work in Fort Myers, Fla., and should return at some point after the All-Star break.