Yost has that option because of Monday's open date and decided to delay O'Sullivan's next start until Saturday against Minnesota.
"I like to get my guys through the first month on a regular rotation," Yost said. "I like to keep the first four starters in a five-man [schedule], it keeps them sharper the first month. They're all healthy, they're all strong. I try to sharpen them up as much as I can. Then I look at the second month and give them days here and there. But the more they pitch, the sharper they're going to be."
So Luke Hochevar will pitch on Tuesday at Cleveland, followed by Jeff Francis on Wednesday and Kyle Davies on Thursday. Then, against Minnesota at Kansas City, it'll be Bruce Chen on Friday and O'Sullivan on Saturday, back in the fifth starter's spot.
In his first start on April 16, O'Sullivan went the first five innings of a 7-0 win over Seattle. In his second start last Thursday, he went six innings and gave up two runs in the Royals' 3-2 win over Cleveland. He had a no-decision in the latter game.
Vin Mazzaro, the guy O'Sullivan replaced as the No. 5 starter, pitched seven shutout innings for Triple-A Omaha on Saturday and sharpened his control (one walk). But that will have no immediate effect on Kansas City's staff.
"O'Sullivan had an opportunity, he did a good job in that spot right now and we'll just leave it like that," Yost said.