From the Boston Herald:
There is support within the organization to deploy the combo of Alex Cora and rookie Dustin Pedroia at second base, while the Sox have explored trade talks for a few veteran first basemen, including Milwaukee's Lyle Overbay and Cincinnati's Sean Casey. Sources indicated that talks are ongoing with the Reds regarding 31-year-old Casey, who is owed $8.5 million next season after batting .312 with nine home runs, 58 RBI and a .371 on-base percentage in 2005. The affable, left-handed hitter owns a lifetime batting average of .305, and has struck out only 467 times in 4,017 at-bats.
Cincinnati is looking for players who could play right away and is believed to have interest in Bronson Arroyo and Queen City native Kevin Youkilis, among others.
I would take Arroyo or Youkilis for Casey. Gladly. If Arroyo was acquired then I'd keep all four outfielders, but of course if it was Youkilis coming back then someone would still have to be dealt.
I'm not even clamoring for Casey to be traded (freeing up his contract might get you a middle reliever in this year's free agent market), but getting either of the two players above would actually be a pretty good deal.