"When I first hurt it, they told me it would be a little while to get back -- it wasn't just a mild strain, It was a pretty significant strain," Oswalt said. "I was hoping to be on the field in five weeks, but it's going to be a little bit later than that."
"We're going to still do stuff. It's not like it was last time. I know the cramping is a sign of slow down, you're going too fast."
Oswalt, 0-4 with a 7.64 ERA before the injury, had hoped to throw Saturday's simulated game at PNC Park, pitch once on a Minor League rehab assignment, and return to the Rockies' rotation. Now it's unclear when he'll be able to throw bullpen sessions, much less return to the mound.
Even if it's late in the season, a return before the end of the season could be beneficial for Oswalt and the Rockies.
Having not received an offer to pitch as a starter last winter, Oswalt didn't sign with the Rockies until May and didn't pitch in the Majors until June 20. It was much like last year, when he joined the Rangers after the season started.
The Rockies, whose original hope was Oswalt would be a stabilizing influence for the rotation, can evaluate whether to make Oswalt an offer to return next year. Oswalt also has said he would like to return to the Rockies, or receive an offer from a team so he can start Spring Training rather than stay home in Mississippi and keep in shape until a team calls.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.