ST. LOUIS – A player with a high pain tolerance and someone who despises missing games, Masyn Winn boldly predicted that he would be in the Cardinals’ starting lineup on Tuesday even though he was experiencing knee soreness that knocked him out of a weekend game.

As has often been the case with Winn when he has gone through injuries, the 24-year-old shortstop overestimated his healing powers and the need to take care of his body when he’s banged up.

Winn was not only out of the lineup on Tuesday when the Cardinals were set to take on the Pirates, but he was away from Busch Stadium getting an MRI on his ailing left knee. As of Tuesday afternoon, the Cardinals were still awaiting the results of the test that should reveal whether Winn suffered structural damage to the knee.

“We want to make sure that if we go day-to-day with him and if he’s pushing through anything – as (pain) is tolerated – that we’re not going to risk anything further,” manager Oliver Marmol said of the testing being done on Winn’s knee. “Depending on what comes back from that (MRI), we should have a plan in place.”

#STLCards SS Masyn Winn is undergoing an MRI on the left knee pain that knocked him out of Sunday’s game, per Oli Marmol. The team is anxiously awaiting the results.

Winn rested on Monday and still felt pain on Tuesday. He is not in the lineup tonight vs. the #Pirates.— John Denton (@JohnDenton555) May 19, 2026

Cesar Prieto, who worked in Triple-A earlier in the season to play shortstop after spending more of his time previously at third base and second, got the start at shortstop on Tuesday night against the Pirates.

Winn was limited to 129 games in 2925 and underwent arthroscopic surgery on his right knee last October. Winn won his first Gold Glove in 2025 after committing just three errors in 501 total chances. This season, he has already committed four errors in 191 chances.

The Cardinals were understandably concerned that Winn’s knee was still sore on Tuesday even after having Monday off.

“He rested yesterday and when he came in today, he was slightly better, but still store,” Marmol said. "So, we wanted to make sure if we’re going to test it out that let’s get some imaging first. Then, we can test it out.”

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Winn's knee pain has lingered since Sunday

Winn left Sunday’s game after racing down the first base line to beat out a double play try by the Kansas City Royals. Soon after hitting the third base line, Winn doubled over in pain and was joined by a medical trainer before leaving the game.

“It almost felt like a cramp when the calf tightened up on me a little bit and they thought it was better to take me out,” said Winn, who had a single and was hit by a pitch before grounding to third base in the seventh inning. “I wanted to stay in, and they told me run and I took one step and thought that it was probably not worth it.”

"Nothing too serious. I'm not worried about it."

After exiting the game with left knee discomfort, Masyn Winn said he expects to be back in the lineup Tuesday.@MatrixMidwest | #stlcardspic.twitter.com/sbsNuvfAlI— Grace Ybarra (@gnybarra) May 17, 2026

On the season, Winn is slashing .255/.331/.353/.634 with a homer, eight doubles, a triple and 17 RBI. Going into the season, Winn raved about how well his right knee felt after playing in pain much of the second of the 2025 season and he had hoped to be more active on the basepaths this season. He has stolen just four bases in five attempts this season, but having a surgically repaired right knee has aided his play this season.

“Last year, we saw him pick his spots, going first to third and with base advancements, he led the team in those areas,” Marmol said. “When he feels fresh and his legs are under him, (running the bases) is a big part of his game. He’s aggressive, he’s smart and he’s explosive. Defensively and on the bases, we’re seeing (health with the right knee) in all aspects of his game.

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