"It's obvious he's throwing the wall extremely well," Rangers manager Ron Washington said. "He's commanding his fastball and getting his secondary pitches over. His numbers show what he's been doing."
Washington confirmed that Harrison will go on the disabled list. What the Rangers haven't decided is what happens when he is ready to pitch again.
But there is a strong possibility that Harrison could end up in the bullpen as the second left-hander behind Darren Oliver. That would allow the Rangers to keep Holland in the rotation permanently.
"It's obvious he's one of the guys we've been trying to get up here," Washington said.
Holland made 21 starts and 12 relief appearances for the Rangers in 2009. He was 6-12 with a 6.23 ERA as a starter and 2-1 with a 5.48 ERA as a reliever. He came to Spring Training as a candidate for the rotation but suffered a sprained left knee early in camp and never caught up.
However, Holland has pitched extremely well in Oklahoma City and the Rangers want him in their rotation. Harrison's injury opens that door.
Harrison came down with soreness in his left biceps tendon during Thursday's start against the Royals. He allowed four runs in five innings and his arm really started to feel sore in his final inning of work. He is now 1-1 with a 5.29 ERA in six starts.
"I'm not sure when I'll be able to pitch again," Harrison said. "The soreness is still there, but we want to take it slow because it's only May. We'll just wait until the soreness goes away."
Harrison was supposed to pitch on Wednesday. Holland could pitch that game or he could be pushed back as far as next Saturday against the Blue Jays. But Washington said the Rangers would like Holland to pitch one of the three games against the Athletics.
Pushing him back to Thursday would allow the Rangers to pitch C.J. Wilson on Wednesday with his normal four days of rest.
The Rangers have not yet officially placed Harrison on the disabled list. There is a possibility they could call up a reliever to fill a spot in the bullpen until it's time for Holland to start. But they don't have a need right now after Wilson's complete game on Friday.
T.R. Sullivan is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.