So, with Brayan Pena scheduled to catch left-hander Bruce Chen, Yost inserted Perez in the designated-hitter slot for the middle contest of the Royals' three-game series against the White Sox.
Regular DH Billy Butler shifted to first base in place of Eric Hosmer, who is 1-for-9 in his career against White Sox starter Chris Sale.
Saturday marked Perez's first career start anywhere other than catcher. A handful of factors made Perez finally serving as the designated hitter possible:
The Royals have three catchers on their roster, thanks to September callups.
Hosmer's struggles against Sale.
Perez is on fire, batting .360 (18-for-50) during his hitting streak.
The disadvantage of Saturday's lineup, of course, is having Butler at first base instead of Hosmer. Butler started at first on Tuesday and committed an error in the third, when he missed a throw from shortstop Alcides Escobar. But Yost said he wasn't concerned.
"I've seen Billy play first base a lot, and that doesn't happen very often," Yost said. "The tough picks, Hosmer's going to make. But Billy [is fine]."