The Rangers are making the switch because it allows Perez to start on his normal four days of rest. Perez had eight days off before and during the All-Star break so they are trying to get him back into his normal routine.
"He threw 82 pitches [in his last start] and we feel this is the best way to get Martin back into rhythm and be consistent," manager Jeff Banister said. "It is more for him than anything else."
Perez is 0-3 with a 10.91 ERA in his last three starts.
Holland throws bullpen
Left-hander Derek Holland threw a 25-pitch bullpen on Saturday, his first time on the mound since going on the disabled list with shoulder inflammation.
Holland will throw at least a couple of bullpen sessions before graduating to live batting practice followed by an injury rehab assignment in the Minor Leagues.
"It was a good first day," Holland said. "There are still a lot of things to improve but all in all, I'm really pumped about the first day."
Holland's next bullpen session is scheduled for Tuesday. Since he is on the 60-day disabled list, he can't be activated until Aug. 20 even though Holland hoped to be back before then.
"It's one of those things, you have to respect the decision that was made," Holland said. "These guys will do everything they can to get me on the field. If that's the deadline, then that's the deadline."
• Texas brought catcher Bryan Holaday to Kansas City because of concerns about catcher Bobby Wilson's health. Wilson felt his right hip muscle grab him during Friday's game, but he was better on Saturday. Holaday is on the disabled list and currently on a rehab assignment at Triple-A Round Rock.
• The Rangers have claimed infielder Matt Duffy off waivers and assigned him to Round Rock. Duffy was hitting .226 with six home runs and 30 RBIs in 74 games with Triple-A Fresno. He went 3-for-11 in limited time with the Astros the past two seasons.
• The Rangers lost the series opener to the Royals on Friday night even though they received an official "quality start" from Yu Darvish. The Rangers had won 14 straight games in which their starter turned in a quality start before the 3-1 loss.
T.R. Sullivan has covered the Rangers since 1989, and for MLB.com since 2006. 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.