If you look at the roster, the Red Sox don't have a lot of holes. The only place they could conceivably use an upgrade is at 3B, but they have internal options that look just as good as what the trade market can offer. Nava is slumping a bit, but he's still been very good against RHP, and Gomes is starting to swing the bat.
We could use a few bullpen arms, but again internal options might be the better route. De La Rosa and Webster could be very good options out of the bullpen. I don't think we should be looking for a closer, but rather fifth or sixth options out of the pen. The rotation has been very solid. Lackey and Buchholz can anchor the front. Dempster, Doubront, and Lester are pretty good options for the back end of the rotation. I don't mean to beat a dead horse, but the only weakness I could possibly see from this team is not having an elite third option for the postseason.