The Rangers flipped Oswalt's start with Scott Feldman, who will now start Sunday, to give the veteran an extra day of rest.
Oswalt, who had an anti-inflammatory injection in his lower back earlier in the week after missing his last start with stiffness in that area, said the decision was fine with him and he feels great.
"I should be ready to go," said Oswalt, who threw about 50 pitches in Friday's bullpen session. "The biggest thing is getting back out there 10 days in between starts and getting a feel of it. Hopefully, it'll fall into sync pretty quick."
Oswalt's return to the rotation became more critical with Colby Lewis set to miss the rest of the season with a torn flexor tendon in his throwing elbow. Lewis had successful surgery on Friday, and there was no ligament damage. He will begin rehab in a couple of days.
Oswalt is now the lone veteran on the staff, but he knows he has to do more than that to be an asset to the club.
"My job is to eat up innings, as many as I can," Oswalt said. "That's what I try to do when I get out there. I think a lot of people don't give credit to the arms we have. We've got some tremendous arms."
Oswalt is 3-1 with a 5.22 ERA in five starts this season with the Rangers. He made his first start with Texas in June. Since giving up a career-high 13 hits in consecutive games, Oswalt has thrown two successful outings, giving up a run in each start.