Willson Contreras' night ended early Saturday against the Cardinals as the Cubs catcher exited with right hip tightness.
Contreras shook his head as he walked back to the dugout in the middle of the third inning, signaling the Cubs dugout he was not feeling right.
Catcher Erick Castillo took over behind the plate in the bottom of the third. The Cubs called him up from Triple-A on Thursday after Austin Romine went on the injured list.
Castillo, who made his MLB debut Thursday, is the longest-tenured player in the Cubs organization — outside of Contreras.
If Contreras does not play in Sunday's season finale, he'll finish with a .237/.340/.438 slash line, 21 home runs and 57 RBIs in 128 games this season.
"It was an up and down season," Contreras said Friday of his individual campaign. "I gave my best. I did my best day in and day out, and that's why I'm going to leave with my head up high."
Contreras has been one of the most durable catchers in baseball this season, ranking seventh in MLB in innings caught (933 2/3) entering Saturday despite missing three weeks post-All-Star break with a right knee sprain.
The Cubs have leaned heavily on him while losing many backup catchers to injury. Castillo is their eighth backup used in 2021.