Jon Daniels said right-hander Neftali Feliz will prepare as a starter when he begins a minor league injury-rehabilitation assignment with Triple-A Round Rock on Sunday, but his role upon returning to the major league club is to be determined.

Feliz opened the season in the rotation but went on the disabled list on May 19 because of a sprained elbow ligament. The Rangers added veteran free-agent right-hander Roy Oswalt after losing Feliz and used nine starting pitchers in June.