Hochevar, the No. 1 overall selection in the 2006 First-Year Player Draft, will take John Bale's spot in the rotation. Bale is on the 15-day disabled list with left shoulder fatigue.
Officially, Hochevar will be recalled from Triple-A Omaha and put on the roster before Sunday's game, and one player will have to be removed.
In three starts for Omaha, Hochevar was 1-1 with a 2.60 ERA. He'll be pitching on regular rest after working six shutout innings on Tuesday night against Nashville.
"Rather than start 'Johnny Whole Staff' -- a bullpen start -- [on Sunday], we'll go with [Hochevar] and reward him for doing very well at Spring Training and also starting well in the Triple-A season," Royals manager Trey Hillman said.
Hochevar, 24, made a strong bid to make the rotation this spring, but he was optioned to Omaha as the Royals opted to go with Bale and Brett Tomko as the fourth and fifth starters.
Hillman said the Royals wanted Hochevar to work on repeating his delivery consistently, a skill considered necessary for success in the Major Leagues.
"When he gets out of his delivery, he gets in trouble in a hurry -- at least from what I've been told," Hillman said. "I've never seen it, because he was pretty dominating in Spring Training."
A rookie, Hochevar was a September callup last season, and he posted a 2.13 ERA and an 0-1 record in four games, including one start.
Hochevar is expected to make at least two starts while the Royals monitor Bale's shoulder problem. Bale is expected to test his arm on Tuesday.
When Hochevar is added to the roster on Sunday, the Royals could return reliever Joel Peralta to Omaha. Peralta was recalled on Thursday, and he pitched 1 1/3 scoreless innings against Oakland on Friday night.
Veteran Hideo Nomo might be at risk, too. He gave up three hits, including a three-run homer, to the A's in Friday night's 13-2 loss, and his ERA rose to 18.69.
Nomo came into the game after Yasuhiko Yabuta had walked four batters, and Hillman noted that Nomo lacked velocity on his pitches.
"For Yabu and Nomo both, you wish for better results last night. Is there some concern? Yes, there's a little bit, but not to a point where we're not going to push the panic button or anything," the manager said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.