BALTIMORE -- Third baseman Kevin Youkilis, who played in his final Minor League rehab game on Monday night, should be activated Tuesday as long as he gets clearance from the doctors.

However, in light of recent developments, highly-touted prospect Will Middlebrooks, who has filled in admirably during the absence of Youkilis, might also stay on the roster.

The Red Sox learned before Monday's game that outfielder Cody Ross will be out for several weeks as he recovers from a fractured navicular bone in his left foot.

There's at least a chance the Red Sox could get creative with both Youkilis and Middlebrooks on the team, perhaps playing Adrian Gonzalez in the outfield at times.

That would open up first base for either David Ortiz or Youkilis, with the other player being deployed as the DH.

"We have talked about it," said general manager Ben Cherington. "We lost a good right-handed hitter today for a while, so it's hard to lose more right-handed hitters. It's a consideration in light of that. We're still talking about it. We'll see how it would work."

There are a lot of things to balance out. Obviously, Boston would have its best possible offense with Youkilis and Middlebrooks both in the mix. But are they sacrificing too much on defense and asking too much out of Gonzalez?

"At a time like this, it's important to slow things down and try to make decisions for the right reason," Cherington said. "We want to do what's best for the team, certainly, but also what's best for the players. It is something we've discussed and talked about what it would be like if we did. At a time when you have a lot of injuries at one spot, sometimes you might have to come up with solutions that you might not have thought of two months ago. We're talking about all sorts of things."

Gonzalez held his own playing right field in Philadelphia over the weekend.

"Yeah, I think Bobby's got a good feel for what Adrian can do," Cherington said. "I think Adrian is comfortable out there. He sees the ball off the bat well. I think Bobby has a good feel for how much he can do that and how to be safe for him and safe for the team."

Asking Gonzalez to play right field in Fenway Park could be a little much.

"Fenway is a little bit more of a challenge, because of the space out there," Cherington said. "Some of the ballparks we play in on the road, there's a little less ground to cover. Maybe that becomes an option. It's not something that we want to do a lot long term. In the short term, perhaps every once in a while within Adrian's comfort level."

The other plus of having Youkilis and Middlebrooks on the roster at the same time is that the former could be eased back in rather than playing a bunch of games without a day off.

"We've got to listen to him and see how he responds," Cherington said. "He's had a couple days off during the short rehab assignment he's been on. He's playing tonight. Kind of see how he does, see how he responds every day. He's obviously been an everyday player throughout his career, so he's used to doing that. He's gone through some things. Bobby will be careful, I'm sure, and if giving him a day here and there helps him, then that's something we can do."

Sweeney takes concussion tests; DL possible

BALTIMORE -- Outfielder Ryan Sweeney underwent more concussion tests before Monday's game against the Orioles and then felt fatigue after taking batting practice.

Sweeney still hasn't been cleared to play, and manager Bobby Valentine said after Monday's 8-6 win over the Orioles that Sweeney could go on the seven-day disabled list that was instituted specifically for players who suffer head injuries.

"I don't know how bad it is," said Sweeney. "I did some of the tests today, and I think I did OK on the reaction stuff. They said when you have something like this, and you overexert yourself and try to do too much, you've got to let your head heal. I did some hitting and some bike, and just kind of felt a little tired today. I've just got to come in tomorrow and see how I feel."

With Cody Ross set to go on the disabled list with a fracture in the navicular bone of his left foot, the Red Sox can't afford to carry Sweeney on the roster if he's unable to play.

Sweeney felt whip-lash symptoms after making a sensational catch on Saturday night against the Phillies. With Sweeney and Ross both out, Che-Hsuan Lin added a hit and a run in his first Major League start.

"I've never had anything happen to my head before, so I don't really know," Sweeney said. "As a player, you want to go out there and play, but sometimes it might not be the smartest thing to do. You've got to watch out for your health."

Dice-K gets shot in trapezius muscle

BALTIMORE -- Daisuke Matsuzaka was with the Red Sox for Monday's series opener vs. the Orioles, one day after receiving a cortisone shot in his right trap muscle as he continues to recover from Tommy John surgery.

As a result of the injection, the right-hander will not make his final rehab start for Triple-A Pawtucket on Tuesday. Matsuzaka will be shut down for a minimum of seven days and will then have clearance to start another 30-day Minor League rehab assignment.

"The same area maybe flared up about three weeks ago," Matsuzaka said through an interpreter. "The same symptoms seemed to clear up, but they came back again. It restricts my movement. That's why I got the shot and hopefully it gets better from here. My rehab, so far, has been going really well. It is a setback, and it's a little disappointing, but hopefully the shot takes care of it and I can continue my rehab from there."

Matsuzaka said he is already feeling better because of the injection. His goal is to pitch a bullpen session as soon as possible.

The Red Sox have not put a timetable on his return. Matsuzaka doesn't plan to return until he is fully healthy.

"I don't want to, and I don't think I can, pitch until I am at 100 percent physically and mentally, and that's the type of patience I need to continue working with," said Matsuzaka, who was 0-2 with a 4.62 ERA in five rehab starts. "I haven't felt 100 percent yet, but I have felt that I'm getting approaching 100 percent, getting closer to 100 percent."

Cook's knee still healing, skips rehab start

BALTIMORE -- Right-hander Aaron Cook has encountered a setback in his return from a left knee laceration. Instead of starting a rehab assignment for Triple-A Pawtucket on Tuesday, Cook will stay on the sideline.

"One corner of the cut's not healing as much as the doctors wanted it to heal," Cook said. "They want to make sure it's completely closed. They kind of just said, 'Let's take it easy for a few days, see if it completely closes and we'll reevaluate.' I was supposed to go out tomorrow and pitch."

It would be easy for Cook to be frustrated. He started the season in the Minor Leagues, because the team took a conservative approach based on his recent history of injuries.

In his season debut May 5 vs. the Orioles, Cook suffered a gash in the second inning while trying to block home plate. The veteran, who is 72-69 with a 4.56 ERA, is keeping things in perspective.

"The doctor put it like this: 'Would you rather lose your leg or miss a couple of more weeks?' I don't want to get an infection in there," said Cook. "We've been doing a pretty good job staying on top of it and being able to do my throwing and running."