The Rangers signed Oswalt after Neftali Feliz's elbow injury in late May. Since then, the veteran righty has made four Minor League starts, and Sunday's was the best. After pitching to a 7.50 ERA in his first three outings, Oswalt threw 100 pitches and 70 strikes over six innings, yielding just two runs and one walk in Round Rock's 4-2 victory.
"I feel like I'm ready. The plan was six starts, but after tonight, I feel pretty well," Oswalt said after Sunday's game. "Everything's coming out of my hand pretty well. The ball's kind of jumping on guys. That's what I was looking for."
Oswalt said he hopes his next stop is Arlington, where the Rangers return Friday after a three-game trip to San Diego.
"He was good ... had a good breaking ball," Washington said. "I think that was one thing that was missing in his other starts. You know he's got a changeup, know he can spot the fastball, so we have a decision to make, but we haven't made it yet."
As the Rangers' rotation stands, Justin Grimm, who earned a win against the Astros in his Major League debut Saturday, would be Friday's starter. Washington said he and his staff have not made a decision on Oswalt or Grimm, though he was adamant that skipping the struggling Scott Feldman -- scheduled to pitch Tuesday night -- is not an option, even with an off-day Thursday to allow the rest of the rotation to catch up on rest.
"I do believe if we decide something on Oswalt, it could change what we have," Washington said. "But we're not going to prematurely do something because we haven't discussed it yet."