Roy Oswalt (hamstring) will throw at least one more simulated game before going out on a rehab assignment. Oswalt is a little behind Tyler Chatwood (elbow), who also threw a simulated game Thursday. He'll throw another sim game over the weekend before likely beginning a rehab assignment sometime next week. Barring a setback, Oswalt should rejoin the rotation in early September.

Roy Oswalt (hamstring) threw three innings in a simulated game Thursday. Like his teammate Tyler Chatwood (elbow), the next step calls for Oswalt to make a minor league rehab start on Sunday. However, it's unclear when he'll be activated. The veteran right-hander has been sidelined for a little over a month with a left hamstring strain.

Roy Oswalt (hamstring) threw 65 pitches in a bullpen session Monday. The next step is a simulated game on Thursday. If all goes well, he could make a minor league rehab start as soon as Sunday. The veteran right-hander has been sidelined for a little over a month with a left hamstring strain.

Roy Oswalt (hamstring) will attempt to throw a simulated game sometime in the "near future." Oswalt experienced a setback with his hamstring Saturday while throwing a sim game, but it was apparently minor. "I think he'll back before too long," Rockies manager Walt Weiss said. "I think he's going to move quickly."

Roy Oswalt experienced a setback with his hamstring Saturday while throwing a simulated game. Oswalt made it through just two hitters before calling it quits. "It's going to take a couple more weeks," said the veteran right-hander. "I want to be out there." He has been on the 15-day disabled list since July 8.

Roy Oswalt (hamstring) threw a successful 36-pitch bullpen session on Tuesday afternoon. Oswalt plans to throw a simulated game on Friday and then head out on a short minor league rehab assignment. He should be back with the Rockies by mid-August.

Roy Oswalt (hamstring) is scheduled to throw a 40-pitch bullpen session on Tuesday. Oswalt said he was at about "80 percent" when he threw 15 pitches in a bullpen session Friday. Barring any setbacks on Tuesday, he should be cleared to face live hitters. Look for him to rejoin the Rockies' rotation within the next couple of weeks.

Roy Oswalt (hamstring) threw a 15-pitch bullpen session at about 80 percent on Friday. "I'm feeling good, no pain," he said. Oswalt will travel with the Rockies and throw another bullpen session during their upcoming road trip. He should be ready for a rehab assignment soon and a return to the team's rotation within the next couple weeks.

Roy Oswalt (hamstring) hopes to throw a bullpen session this weekend. Oswalt thinks he's ahead of schedule after doing resistance training with weights, increasing the pace of his running and playing long-toss on Monday. "It's going pretty well," Oswalt said. "They're looking at me kind of funny, like it's going too fast. It's not going fast enough for me. I know they don't want to push me until it gets completely healed, but it feels great right now." If Oswalt is able to throw a bullpen session this weekend, a return in early August is likely.

Roy Oswalt (hamstring) ran lightly in the outfield and threw on flat ground Thursday. Oswalt is easing back into activity as he tests out his left hamstring strain. There's no timetable for the veteran right-hander's return, but early August seems like the best bet.