ST. PETERSBURG -- At a time the Red Sox are getting spotty results in the rotation after the top two of Josh Beckett and Jon Lester, there is some encouraging news on the disabled-list duo of Tim Wakefield and Daisuke Matsuzaka.

Wakefield, who has been out since the All-Star break with a lower back strain, is tentatively scheduled to throw a side session before Wednesday's game.

Matsuzaka, who last pitched for the Sox on June 19, is expected to throw his first side session by the middle of next week.

As far as Wakefield is concerned, his back is basically all better. What has held him up is a feeling of weakness in his left leg, which seems to be a nerve issue related to the back problem.

"My calf has shut down," said Wakefield. "There's zero strength in there right now. The soreness in my calf has gone down, and I feel better when I walk even though I'm limping a little bit."

The problem for Wakefield at the moment isn't so much pitching, as it is being able to field his position.

"It felt better today than it had in Baltimore," Wakefield said. "Throwing a side for the first time tomorrow, we'll see how that feels and then go from there."

Meanwhile, Matsuzaka has been on an extended rehab program at the Red Sox's Spring Training complex in Fort Myers, Fla. But he took the drive over to St. Petersburg and will spend the next two days with the Sox.

Matsuzaka is 1-5 with an 8.23 ERA in his eight starts this season. He never seemed to have enough strength in his shoulder after pitching for Team Japan in the World Baseball Classic.

During the time he has been down, Matsuzaka has been working as much on overall body strength and conditioning as he has with his getting his shoulder back up to snuff.

He played catch at 120 feet with Red Sox pitching coach John Farrell on Tuesday.

"His arm looks strong," said manager Terry Francona. "I think he feels pretty good. He certainly looks good physically. We'll keep this progression going."

Matsuzaka won't return to the Red Sox until September. Wakefield, the team hopes, will be much sooner than that.