But during the game, Rosario was light on his feet and heavy with his swing. His RBI double and impressive solo homer to center field -- the 19th of his rookie season -- were key hits in an 8-6 victory over the Brewers.
Rosario, 23, injured the ankle when he tumbled awkwardly while blocking a pitch at San Diego on July 20. The pain has affected his production to a degree. Already struggling fundamentally, Rosario has been less mobile. In 15 games since the injury, he has hit .200 and seen his season batting average drop 10 points to .244.
But Rosario has hit four home runs, driven in eight runs and knocked three doubles since the injury, and in the 15 games he has played in pain he has lifted his season slugging percentage a point, to .533.
"I don't know what fatigue is or any of those things, but I'm playing, and I like to play," said Rosario, who did not start Wednesday afternoon's game against the Brewers. "When the game starts, the pain goes. It comes back after the game, but not when I'm playing."
Rosario can't let the pain hamper him as he tries to finish his development at the big-league level -- a difficult task for a young catcher, even when he is healthy. It's even tougher with a struggling pitching staff.
Rosario leads the Majors with 14 passed balls. The Rockies also went into Thursday leading the Majors with 66 wild pitches -- 13 more than the second-place White Sox -- and were fifth in baseball in walks with 399. So Rosario has had difficulty catching some pitches, but it's clear the pitchers have had trouble hitting a target.
"The pitchers' command fluctuates periodically," Rockies manager Jim Tracy said. "He's recognizing the fact that when he's set up for a pitch and it doesn't go there, he has to be able to shift, respond and get to it, rather than have it go to the screen on too much of a regular basis."
Toward that end, Rosario said, he is setting up with his feet flatter, which allows him to push to the side quicker. Although his ankle injury makes pushing a little more difficult, he might also be safer with his feet flatter, rather than on his toes.
Rosario said he and the pitchers will look much better as they gain experience.
"Sometimes when you're young and you're working with young pitchers, they might not have the confidence," Rosario said. "But it's going to come. I know them and trust them, and they trust me and know me from coming up in the Minors."
Rosario will be there for them, no matter how much it hurts.