"I don't have a long guy," Yost said. "I got to have some protection."
Junis, ranked as the club's No. 5 prospect by MLBPipeline.com, has a 6.00 ERA in six starts for the Royals this season. His last start was on June 29, and he also made two one-inning relief appearances earlier this season.
With a lack of fresh arms in the bullpen, Yost was prepared to use lefty Travis Wood, who is scheduled to start on Sunday, in Friday night's 7-6 walk-off win in 10 innings against the White Sox.
"My whole bullpen has been used. If something happened early, I've got to have some length," Yost said. "... We'll go short on the position player side for a day or two and get everything back in order, then go from there."
Wilson Alexander is a reporter for MLB.com based in Kansas City.