He threw off the mound on Monday without any problems and will do so again on Wednesday during the Rangers' pitching minicamp at the Ballpark in Arlington. He is throwing at about 80 percent, but that's normal for mid-January.
"So far so good," Harrison said. "Every day is getting better. It's a matter of getting repetition and getting back in a game."
Lewis is not at the minicamp but is still in a throwing program. The Rangers signed him to a Minor League contract in the hope that he is fully recovered from two years of injuries that included surgery on the flexor tendon in his right elbow and another to address the chronic pain in his right hip.
Pitching coach Mike Maddux watched a video of Lewis throwing on Tuesday and said he could see a big difference after the hip surgery. Maddux said Lewis is getting better extension in his delivery.
"It looked like Colby went into a time machine and found a fountain of youth," Maddux said. "He'll be on a little different program. We'll have to listen to him and get with our medical team to meld him into our Spring Training program. We're in uncharted waters, but if anybody can find the shore, it's Colby."
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.