"No limits," Rangers pitching coach Mike Maddux said. "Go out and compete ... produce."
Lewis hasn't pitched in the Major Leagues since July 18, 2012. He had flexor tendon surgery on his right elbow in 2012, and a hip replacement last season.
Lewis is farther along than Matt Harrison, who had his first medical rehabilitation start cut short by rain on Thursday night. The Rangers wanted Harrison to throw four innings and 65 pitches for Double-A Frisco against Northwest Arkansas. Instead, he made it through two innings and 42 pitches. He is scheduled to pitch again on Tuesday at Northwest Arkansas, with the goal again being four innings and 65 pitches.
"Mother Nature didn't cooperate but we're staying on schedule," Maddux said. "He might get a bigger bullpen [session] than normal tomorrow."
Harrison started the season on the disabled list while finishing off his recovery from two back operations a year ago to repair a herniated disk. He likely needs 3-4 more starts before he is an option for the Major League rotation.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.