"If we start abusing these guys, we're going to kill them. We can't," Yost said. "We have to be smart about our usage with them without abusing them. They've all been worked to a high degree here, especially in the last week."
The Royals used seven relievers in Sunday's 15-inning victory over the Cardinals -- Kelvin Herrera, Jose Mijares, Aaron Crow, Greg Holland, Tim Collins, Nate Adcock and Jonathan Broxton.
Yost said Collins, Holland, Herrera and Broxton were most likely unavailable to pitch Monday. Collins, Holland and Herrera pitched on Saturday. Broxton pitched three innings over the weekend, including two on Sunday to pick up the win.
Right-hander Louis Coleman and left-hander Tommy Hottovy figured to see work on Monday if starter Jonathan Sanchez exits early. If there's a closing situation, Yost said Aaron Crow would probably handle it.
With just 11 position players, the Royals might need to get creative in the later innings.
Yost said Collins and Holland are athletic enough to play in the field. He also mentioned that Broxton could be used as a pinch-hitter. For his career, Broxton is 0-for-5 at the plate with two walks.
"We can get through it," Yost said.
If third baseman Mike Moustakas, shortstop Alcides Escobar or second baseman Yuniesky Betancourt get hurt, Yost is prepared to move Alex Gordon to third or first and Moustakas to second base or shortstop.
The Royals had catcher Brayan Pena, outfielder Mitch Maier and first baseman Eric Hosmer on the bench.
"We've got options," Yost said.
The Royals will reconsider their roster on a day-by-day basis. Yost said the Royals' bullpen should be in good shape by Thursday, an off-day.