Harrison began his assignment on Wednesday by throwing five innings for Triple-A Round Rock against Reno. Harrison allowed two runs on five hits and a walk while striking out four. He threw 78 pitches. The outing comes on the one-year anniversary of Harrison undergoing spinal fusion surgery to correct back problems that limited him to six Major League starts in 2013-14.
"The back felt good," Harrison said. "My arm felt good. I've got to figure out what I can do to get my velocity back up. I haven't been able to get as much power in my legs. It's not going to happen overnight, but hopefully by the end of the month. I'm getting outs, just a little different way. I threw and got off the field healthy. It was a good day."
Ryan Rua, who has been on the disabled list since April 11 because of a fracture in his right heel, was also expected to begin a rehab assignment with Round Rock on Wednesday. But he had trouble getting to Reno because of travel issues.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.