Second baseman Dustin Pedroia (sprained right thumb) took batting practice during Thursday's workout at Tropicana Field, hitting a few pitches over the fences.
"It's a good sign. He feels a lot better, and he's going to ramp up his activity over the weekend," general manager Ben Cherington said. "Hopefully, if all goes well, he'll be able to join us on or not too long after his eligible date."
Third baseman Will Middlebrooks (sore left hamstring) participated in Thursday's workout and should be ready to return, as expected, for Friday's series opener against the Rays. Manager Bobby Valentine said before the workout that Middlebrooks was "real close."
Valentine said the premiere of "Ballplayer: Pelotero," a documentary he produced about baseball in the Dominican Republic, went well, though he was "a little" surprised by the comments made by Commissioner Bud Selig. In Kansas City on Tuesday, Selig said the film contained "a lot of things that were inaccurate."
Valentine said the six-man rotation the Red Sox will utilize coming out of the break is "probably" just a temporary thing and a way to keep his starters fresh with a longer break.
Twenty-one of the 25 players on Boston's active roster were at Thursday's optional workout at Tropicana Field. Josh Beckett, Aaron Cook, Vicente Padilla and David Ortiz, who is coming off the All-Star Game, were not in attendance.