"We want him at full strength," Rangers manager Ron Washington said. "We want to make sure we find out what this is and give him a chance to fully recover."
Holland is 5-4 with a 5.10 ERA on the season, and 2-2 with an 8.38 ERA in his last four starts.
The Rangers decided to replace him with Ogando, who was 13-8 with a 3.51 ERA in 29 starts and two relief appearances last season while being selected to the American League All-Star team. They moved Ogando to the bullpen this season after Yu Darvish was signed as a free agent, and left him there even after Neftali Feliz went on the disabled list with a sprained right elbow.
Now Ogando is going into the rotation for Holland. The other option was rookie left-handed reliever Robbie Ross, who was a starter in the Minors. Scheppers was called up from Triple-A Round Rock to fill Ogando's spot in the bullpen.
"For what we have to choose from, Ogando has more experience," Washington said. "He's done it at the Major League level, and it's something he wants to do. Robbie Ross is our only left-hander in the bullpen, we don't want to do that with him. It's more of an experience factor and the job Ogando did last year. We want to give him the opportunity."
Ogando was stretched out as a starter in Spring Training, but has worked exclusively as a reliever during the regular season. He has made 29 appearances and is 1-0 with a 2.27 ERA. Opponents are hitting just .189 off of him. He threw 30 pitches over 1 2/3 innings in his last outing against the Athletics on Tuesday, and his season high is 39.
Ogando said he thinks he can give the Rangers as many as 70 pitches on Sunday, but Washington said he doesn't want to put a number on it.
"We'll see how long he can take it," Washington said. "If he can pound the strike zone, make them swing the bat and get quick outs, he can get us through five innings. We'll be happy with that."
"It's just a matter of how long my stamina keeps going," Ogando said. "The transition is not that big of a deal. I'm getting a chance to start, which is what I want to do. I understand you have to crawl before you walk and you've got to build up. I'm just taking it start to start."
The Rangers still have Roy Oswalt in the Minor Leagues, and he'll start on Thursday night for Triple-A Round Rock in Omaha. It will be his second start since being signed by the Rangers last week, and the original plan was for him to get at least four starts in the Minors.
That is still the tentative plan.
"My intention is for him to do what he needs to do to get ready to pitch," Washington said. "I don't know if that will change, but my thinking is he'll stay on schedule."
Scott Feldman, who replaced Feliz in the rotation, is starting on Saturday. Feldman was knocked out of his last start in the second inning, and he has yet to pitch past the fifth in any of his five starts. Washington said he is not concerned about having Feldman and Ogando pitch back-to-back. The Rangers are off on Monday.
"I believe each day I show up at the ballpark, whoever we have out there will do what we need them to do," Washington said.
Scheppers will be making his Major League debut. Scheppers, the 44th overall pick out of Fresno State in 2009, was 1-2 with a 3.72 ERA and nine saves for Round Rock.
"I'm definitely excited," Scheppers said. "It's unfortunate that I'm up here to take somebody's spot because of injury, but it's definitely a dream come true. I'll make the most of it."
Opponents hit .270 off Scheppers at Round Rock. He also walked just four batters while striking out 27 in 29 innings. Most important for him is to keep his fastball down in the zone. If he does that and uses his above-average slider effectively, Scheppers can be dominating.
"I've had a couple rough outings, but for the most part, I think I've thrown the ball well," Scheppers said. "My rough outings have come because the ball was definitely up. If I keep it down, the offspeed stuff will play."
To make room on the 40-man roster, the Rangers designated Triple-A reliever John Gaub for assignment. Gaub, acquired by Texas on a waiver claim from Tampa Bay on May 24, has pitched 4 1/3 scoreless innings over five appearances since joining Round Rock. The Rangers have 10 days to trade, release or outright Gaub to the Minor Leagues.