He was then called upon for a leadoff pinch-hit at-bat in the eighth. Stanley answered with a line-drive single to right-center off Brewers setup man Jonathan Broxton. He scored later in the inning, but the Cardinals fell 6-3 to the Brewers..
"[Manager Mike Matheny] told me to be ready at the beginning of the game, and then as the game started rolling along, I got a pretty good feeling that I could possibly enter," Stanley said. "Then it happened. … I think it happened. Did it?"
He was assured that it did and would later receive an authenticated ball from his first hit as tangible proof.
"Just a good first day for him," Matheny said.
Stanley, 26, participated in Major League Spring Training and was then assigned to Memphis for the first time in his career. In 15 games there, he hit .216/.298/.333.
Molina, who was pulled from Friday's game in the fifth inning, did not play either of the two weekend games, though he was available to pinch-hit on Sunday.
"He's feeling better, but we just need to take at least another day," Matheny said. "He can hit. He can run. But squatting is the issue right now."
Molina is hopeful that he'll be back behind the plate on Monday, when the Cardinals open a 10-game homestand against the Phillies.
Along with Molina, both Matt Holliday and Jon Jay were absent from Sunday's starting lineup. Matheny noted that neither outfielder is injured, but rather that he wanted to find a break for both amid this stretch of 20 games in 20 days. Jay ended up entering in the third inning as an injury replacement for Jason Heyward.
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, follow her on Twitter @LangoschMLB and like her Facebook page Jenifer Langosch for Cardinals.com. This story was not subject to the approval of Major League Baseball or its clubs.