Harrison said he'll make his next rehab start Friday with Triple-A Round Rock. He expects to bump it up to five innings and 65 to 70 pitches. Harrison threw just 31 pitches after three innings, allowing the left-hander to pitch in the fourth. Harrison allowed a leadoff single in the inning, but recorded consecutive outs on a flyout and a swinging strikeout to end his outing one pitch shy of his 45-pitch limit. Harrison's fastball consistently hit 90-91 mph, and he topped 92 mph once in the second inning.
"Hopefully that velocity increases a little more," Harrison said. "Usually I pitch around 93. I feel like I'm getting there. I did feel like I had a lot more energy today. I just felt like the ball was coming out of my hand better and I had more confidence in it today than I had last time."
The left-hander needed just nine pitches to retire San Antonio in order in the first. He had two swinging strikeouts, including one to end the inning. Harrison came back out in the second attempting to regain the tempo he had in the first but allowed a four-pitch leadoff walk. The runner scored on a two-out single that danced down the first-base line.
"I was trying to find it, and it got better out of the stretch," Harrison said of his tempo. "I think my best command today was out of the slide-step, which is kind of weird. ... It's going to happen at times where you don't have it, but as long as I can have it more consistently, I'll be pleased with that."
Harrison said the tempo was better in the third and fourth innings as his arm caught up to his body. He retired San Antonio in order in the third on nine pitches again, including a strikeout on a 90 mph fastball.
"I'd like to be back as soon as possible, but it's a process and I have to build myself back up," Harrison said. "At this point it's really [getting] my arm strength back up and throw multiple innings. At this point, I still got a ways to go but if things keep going the way that they are, hopefully I can get back up there soon and get a chance to help the team win some ballgames down the stretch."
The Rangers starting pitcher underwent two surgeries in April and May to repair a herniated disk in his back. Harrison said he hasn't had any back issues over the last three weeks.
"In the time before that, I was pretty much thinking that I was going to get ready for Spring Training next year," Harrison said. "Things weren't going well at the time, but I had a turning point a few weeks ago and it progressed fairly quickly."
Neftali Feliz will also make his second rehab outing Monday in the Rookie-level Arizona League. He will pitch one inning, as he recovers from Tommy John surgery last August.