According to Ken Rosenthal, the Red Sox have shown interested in first baseman Tony Clark. Clark slugged .511 last year in 221 at bats for the Arizona Diamondbacks. But Clark only got on base at a rate of .310 last year and will turn 36 in June. Clark likely wouldn't be a first choice of the Red Sox, as he played rather miserably for them in 2002, and he can only play one position.
The Red Sox have also shown interest in Ryan Klesko, Bobby Kielty and Brad Wilkerson. But if they can't fill up the rest of their bench with free agents, they may look within the organization. I've already stated my desire to see outfielder Brandon Moss in the team in 2008.
The Red Sox could also try first baseman and left fielder Chris Carter for their bench. Carter hit .324/.383/.521, with 18 home runs at the Triple-A level before being dealt to the Red Sox. But his defense is rather poor.