With the acquisition of Bobby Jenks on Thursday, the Red Sox' bullpen went from being one of the team's biggest problems, to a nearly finished product. The addition of a closer-quality reliever can do that, much like the addition of an ace to the rotation, pushing back most of the pen one spot so they have to be used less often, and only in emergencies. Still, with only five spots truly set in stone, the Sox could still have a few moves in store.
One thing that seems for sure is the Sox are not going to be picking up Brian Fuentes. With the lefty seeking a Scott Downs-level deal and the Red Sox not having been willing to commit to that for Downs himself, Alex Speier has indicated that Boston just isn't that interested any more.
A much more likely acquisition at this point would be Dan Wheeler. A local product (hailing from Rhode Island), Wheeler projects to be much cheaper, and could provide a solid fourth man in the pen on just a one-year deal. There are some questions about his peripherals, and how well he will play in Fenway, but it's hard to pass up the possible value a one-year contract would provide.
What is noticeable about the Sox is their lack of a clear lefty. Hideki Okajima is gone, and recently re-signed Andrew Miller is not likely to start at the major league level. A possible solution to this problem is Felix Doubront, who the team has indicated could enter the season in the bullpen instead of as a minor league starter. Doubront held 37 opposing lefties to just a .576 OPS last year, but with the fragility of the rotation in recent years, the Sox may be more comfortable having him stretched out just in case.
Otherwise, expect the Sox to make only a few small depth moves, with most of the acquisitions never seeing major league time. The most potentially impactful pickup would likely be Taylor Buchholz, who the Sox claimed off of waivers and then released earlier in the month to free up room on the 40-man roster. If they choose to bring him back like they did with Andrew Miller, Buchholz could well return to his dominant pre-injury form 2008, when he threw 66 innings with a 2.17 ERA in Colorado.