The Boston Red Sox are looking for depth at first base, but, given the constraints of their roster on both the 25- and 40-man rosters, that depth is going to need to come in the form of minor-league deals and non-roster invites. While Mark Hamilton has already been brought on board for that task, the Red Sox hit the market once again on Thursday, bringing in Lyle Overbay. According to the Boston Herald's Scott Lauber, Overbay can, like Ryan Sweeney, opt-out of the deal if he isn't on the major-league roster by the end of spring training. It's likely that Overbay is there for one reason: it's better to have him and not need him around, then to need him and not have him. If Mike Napoli's hip condition gets cranky right out of the gate, the Red Sox will need someone to fill the hole, even temporarily. If, however, he is healthy coming out of spring training, then the presence of Overbay isn't as significant. Overbay might also find that no one else needs his services after spring training -- someone else would need to have room for a player who was still a free a couple weeks before spring training begins, after all -- and stick around in Triple-A Pawtucket if he feels he has a better eventual chance of being in the majors there than anywhere else. Neither situation is a given, but things would work out well for the Red Sox if they were able to have someone with Overbay's experience in the organization, but off of the 40-man.