ARLINGTON, Texas -- For Matt Harrison, 2012 was a good year. He won 18 games and showed he could make at least 30 starts for the second straight season. He was consistent, giving his team at least six innings of quality baseball nearly every outing and sporting a 3.29 ERA by the time it was over. It was after that season that Harrison earned a long-term deal with the Rangers.

Then the injury bug halted his momentum. He had one more surgery than starts in 2013 -- two back surgeries and surgery for thoracic outlet syndrome -- and missed nearly the whole season. His return in spring training was slowed by some back stiffness, forcing him to make his debut three weeks into the season.

Now, Harrison is searching for what he had in 2012, knowing that's the starting pitcher the Rangers need in the rotation.

"It's getting there," Harrison said. "Sometimes it's hit-and-miss with the mechanics. I'm trying to get back to where I was in 2012 and slowly but surely, it's getting back there and it's little tweaks here and there to fix stuff. I want to get better day-to-day to get back to where I was before."

Harrison lasted only 4 1/3 innings thanks to a high pitch count in Anaheim last week. He gave up three runs and 10 hits with three walks and three strikeouts in a 5-3 loss.

Harrison blamed back mechanics, saying he was opening up too much, causing his pitches to move laterally more than they should. He had an extended bullpen session -- 70 pitches -- to fix the problem.

"At the end, it was much better," Harrison said.

It's the first time Harrison has pitched on regular rest, rather than extended rest. He thinks that could help him get on a roll with his in-between start routines.

He'll go up against Rockies lefty Franklin Morales at 7:05 p.m. tonight.

Monitoring Choo: Rangers manager Ron Washington says Shin-Soo Choo's sprained ankle won't be 100 percent for a while, possibly the whole season. So it's something Choo will monitor and deal with as he plays.

"The way he gets on the bag, he's going to have issues with it," Washington said. "He'll get it wrapped up. Can we afford to give him three weeks? Nope."

Washington will try to help when he can by giving the outfielder some days at DH, as he did Wednesday. That gets him off his feet some in the outfield. But Choo has been one of the club's most consistent offensive players -- a rarity for the Rangers this season.

Location, location, location: Washington says that Alexi Ogando's struggles are all about location. He's not concerned about his stuff, noting that his velocity is good and that his slider has bite.

"He's healthy," Washington said. "He's just got to do better with his location. It's a matter of him toeing the rubber and doing it."

Ogando's pace on the mound has slowed as he has struggled, something Washington plans on discussing with his reliever.