The Post-Gazette reports that the Pirates could pursue a number of "familiar faces" this offseason, the most likely of these being John Grabow, who would be the sort of reliable lefty that who could be useful for the Bucs. One thing to keep in mind here is Grabow's free agency status; Elias, who does the rankings that determine compensatory picks, could make Grabow a Class A free agent, which essentially means that the Bucs would have to give up their second-round pick if they signed him after the Cubs took him to arbitration. The Pirates don't have any business giving up their second-round pick at this point, so if Grabow is a Type A, I can't imagine the Pirates would sign him. A Tigers blogger reverse-engineered the Elias formula and found a couple months ago that Grabow was on track to be a Type A, and he's pitched well since then. For that reason, I think he probably won't end up back with the Bucs.
(If you're curious about why the Bucs would trade Grabow if he were on track to be a Type A, by the way, consider that teams are valuing draft choices more and more highly, and might not sign Grabow at all if it means giving up a second- or first-round pick. The likely outcome in that scenario might be Grabow accepting an arbitration offer from the Pirates, and their trying to trade him again next year. In fact, if he does turn out to be a Type A, the Cubs offering arbitration and Grabow accepting are pretty strong possibilities.)
The P-G also reports that the Bucs could have interest in Jack Wilson or Freddy Sanchez. Sanchez would seem to be the more likely of the two, given that Ronny Cedeno has done a pretty fair Wilson impression in Jack's absence. I'd be surprised to see Sanchez return if his best friend Wilson doesn't come back, though; I was watching the Giants play the other day and saw Sanchez leaning over the dugout railing wildly cheering on his teammates. That might not mean anything, but when you see something like that it's hard not to wonder about Sanchez's willingness to play for a team that assuredly won't be in playoff contention next year.
Rick Ankiel is, to me, the most interesting player in the article--he'd be a good fit in left field for the Bucs, since he's a very good defensive outfielder, and he's coming off a very poor season, so he might be in the Pirates' price range. It's possible to see him rebound a bit, hit 20 or so homers, and be the sort of player a lot of people think Nate McLouth was--a slightly-above-average hitter who plays good defense. Unfortunately, he's represented by Scott Boras, who's tough to work with, and he's 30 and controls the strike zone very poorly. He'd be a gamble, and given his agent, he might not be a gamble worth taking.