Schumaker began the season on the disabled list with an oblique strain, and he first entered the lineup Friday. His return was short-lived, however, as he ran into the center-field wall on Pirates leadoff hitter Alex Presley's eventual inside-the-park home run.
He pinch-hit in Sunday's victory, singling to center and eventually coming around to score.
"He was wanting to get in there in the worst way, so it's nice to get him [in there]," Cardinals manager Mike Matheny said. "Guys were pretty excited for him, too. He didn't expect to start the season on the DL, then come back for two pitches, then go back in the trainer's room. So it was good for him and I'm excited to watch him get out there tonight."
Schumaker concluded Monday's game 6-for-11 with a double in his career against Cubs right-hander Matt Garza, who started the series opener.