"I'm going to stay with Sal, the way he's swinging the bat right now," manager Ned Yost said.
Through Saturday night, Perez was batting .336 in 35 games, and had hit in 14 of his last 15 games (.417) and had nine RBIs in eight games.
That will limit playing time for newly arrived Manny Pina and backup Brayan Pena.
Yost said that results by the recent callups won't be weighed too heavily.
"Nothing's do or die," Yost said. "These kids are coming to Spring Training next year with the opportunity to make the team. It doesn't matter how good or how bad they do at this time."
What is more valuable, according to Yost, is learning the personality and makeup of the young players.
"That's what this is all about," Yost said. "This is about learning your players, personally and professionally. This is not just about what can you do for me on the field. You have to learn them, start to develop a professional relationship with them. Understand who they are, what they're about, because everybody's different. You push everybody's buttons a little bit different. You don't treat everybody the same, and you've got to know the person."
If a hitter goes 0-for-3 or 3-for-3, for example, Yost wants to know how he handles both success and failure.
"It helps to a great degree," he said. "You have to be able to understand a person to get them to perform."