Beltran is a career .299 hitter at Kauffman Stadium, where he played his home games for the first seven years of his career.
"He does a pretty good job of evaluating [his own status]," Matheny said. "I know when he tells me he's dealing with something, I don't push it. I take those opportunities to get somebody else in, and he'll let me know when he's ready to go."
Beltran, hitless in eight at-bats during this series, ranks second in the National League with a .485 batting average with runners in scoring position. He leads the Cardinals with 10 homers and 29 RBIs this year.
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.