Is Mike Lowell, who has a surgically repaired right hip, going to get more rest than he wants with LaRoche on board?
What becomes of backup first baseman-outfielder Mark Kotsay, who, like LaRoche, is a left-handed hitter?
Ultimately, manager Terry Francona will have a busy couple of days huddling with players and with general manager Theo Epstein to determine the best course of action going forward.
"You know, it's kind of one of those things where in talking to Theo -- we talk every day -- there's uncertainty with our health, and I think there's some concern in the organization about enough depth, where if something does happen, where do we go?" Francona said. "So in the meantime, it seems like we have extra players, which is something I need to deal with and communicate and do a good job and make it work really well. That's the idea."
The Red Sox are off on Thursday and will spend that time determining who comes off the roster or is placed on the disabled list to make room for LaRoche.
"He's going to join us for our game up in Boston on Friday," said Epstein. "That will give us time to sort out our healthy bodies from the not-so-healthy ones and sit down with the staff and make a corresponding 25-man roster move."
After a strong start to the season, Lowell was placed on the disabled list on June 30, at which point he had fluid drained from his hip and an injection of a medication called Synvisc. The third baseman was activated on Friday, but his hip isn't likely to be 100 percent until next season.
Lowell didn't seem quite sure how the addition of LaRoche would impact his status as the team's everyday third baseman. It is expected that Youkilis will play third base at least on some of the occasions LaRoche is in the lineup.
"I spoke to Theo, and he told me they're always doing what they can to upgrade the team, and I'd question him as a GM if he wasn't," said Lowell. "That's his choice. We'll just see how it plays out. I really don't know how it's going to play out. If I'm in the lineup and I'm hitting, I'm probably going to stay in the lineup and hit. It's not really that big a deal to me."
At the very least, there is now a logjam that didn't exist before.
"I think we're trying to add some depth to the team, some power from the left side and I would assume versatility," said Lowell. "How it's going to affect me? We'll see. We're going to try to put the best team out there to win, so whoever that is is going to be playing. I don't have a crystal ball, so I have no idea how it's going to play out."
Does Lowell feel extra pressure to produce now that LaRoche is in the fold?
"I don't view it as a challenge -- no I don't," said Lowell. "I relish my own competitiveness. If I'm motivated by outside forces, then I think I have a problem."
Kotsay -- who started at first base on Wednesday, with Lowell getting the night off -- is another player who is in limbo.
"We've had discussions," Kotsay said. "I really don't want to talk about that ... but like I said, the organization is going to make some decisions tomorrow, and I think that's been addressed by Theo and we'll let it play out. Obviously, you always have a concern any time you're a role player on a club and they make an acquisition. For a player, you realize it could [impact] your future. The cards could play out unexpectedly, and if that's the case, that's the reality of the business. You deal with it and you move forward."
Just how things do move forward should be made clearer by Friday.
"It's one of those situations where you have a lot of guys that can and should start and obviously not enough spots," said Red Sox left fielder Jason Bay. "You come into the second half of the season, guys get tired, things happen. A lot of the times, these things work themselves out."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.