PHILADELPHIA -- Roy Oswalt would like to pitch during the stretch run of the regular season and into the postseason.

He'll soon find out if that will be possible.

Oswalt will fly to Dallas on Friday morning to meet with spine surgeon Dr. Andrew Dossett and receive a second opinion on his back.

An MRI last week showed mild bulging discs in Oswalt's back. He wants to be sure he can start a strengthening program and pitch this season without the risk of rupturing a disc and needing surgery.

If there are no surprises during the visit, Oswalt will likely start a series of injections to help strengthen his back.

He could return by August.

In other injury news, Phillies general manager Ruben Amaro Jr. said right-hander Ryan Madson may not be ready to return Monday, the first day he's eligible to come off the 15-day disabled list.

Madson has been dealing with a bruise on his right hand since getting struck with a line drive May 20 against the Rangers.

He will likely need a couple rehab assignments, Amaro said.

If Brad Lidge can get through a couple more bullpen sessions without any setbacks, he'll be ready to start a rehab assignment, Amaro said.

"Those are big ifs," Amaro said. "He hasn't pitched yet, so we'll see."

Joe Blanton is working out down in Clearwater, Fla., but he can't go more than a couple long-toss sessions without feeling tightness, limiting his progression.

"We're not going to get him out on the mound unless he's 100 percent and he's feeling like there's no stiffness or discomfort," Amaro said.

Worth noting

• With a win Thursday, it would be the first time the Phillies have swept the Red Sox since 2000, when they took three straight June 2-4 at Veterans Stadium.

• Jon Lester entered Thursday's game 1-0 and has allowed one earned run over 14 innings in two starts against the Phillies.

• Cole Hamels is looking for a little run support in Interleague Play. In two starts, he's 0-2 but has allowed only four runs in 14 1/3 innings.