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Ranking Cardinals Top Five MLB Debut Seasons in 2026
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- Ranking Cardinals Top Five MLB Debut Seasons in 2026
The St. Louis Cardinals committed to using 2026 as a season for opportunity, development and growth and then they went all in on that promise by giving 13 of their Minor League prospects a shot to make their Major League Baseball debuts this past season.
Several of those players gave a potential glimpse into the future for a Cardinals franchise determined to build around its cluster of young players and a Minor League system that is teeming with blossoming talent. Even though the Cards promoted more than a dozen players in 2026, more rookie debuts could be on the way from a Minor League system – led by slugging catcher Rainiel Rodriguez and power lefty Liam Doyle – that was ranked No. 2 by Baseball America and No. 4 by MLB Pipeline.
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No player in the history of baseball ever had a debut quite like the one authored by 6-foot-2, 235-pound slugger Joshua Báez on Aug. 15 at Wrigley Field. With more than 30 family members and friends looking on for his debut, Báez smashed home runs in the first three at bats of his career. In succession, he homered off the first pitch he saw, he homered off a 3-2 pitch and he homered to the opposite field.
While that one-game performance was one of the biggest highlights of the MLB season, it wasn't even close to the best debut season for the Cardinals in 2026. Here is a ranking of the top five MLB debuts by Cards rookies over the past season.
1. JJ Wetherholt
The top-ranked prospect in the system from the time he was the No. 7 pick in the 2024 MLB Draft, Wetherholt backed up the hype with a strong rookie season. There were hopes that he would become the first Cardinals player to win the Rookie of the Year since Albert Pujols in 2001, but he will likely lose out to Cincinnati Reds infielder Sal Stewart following a poor finish that was partly because of right wrist tendinitis. Still, Wetherholt homered in his first MLB game, had a walk-off single in his second game and crafted his first multi-homer game in his first month. He hit 17 homers and stole 14 bases in 15 tries and he was even better defensively where he set a rookie record (since 2016) with 25 Outs Above Average. No Rookie of the Year award, but he should be the second rookie Gold Glove winner in the storied history of the franchise.
JJ Wetherholt could become just the second rookie in the history of the Cardinals to win a Gold Glove. -- Charles LeClaire-Imagn Images
2. Leo Bernal
The Cardinals called up prospect Jimmy Crooks first, but for a reason. They wanted Bernal to learn how to take charge during the pregame meetings with pitchers. Then, Bernal got his MLB chance on Aug. 31, and he certainly did not disappoint. He had a two-run double in his first game and a home run in his second game – Cardinals' wins over Los Angeles at Dodgers Stadium. Late in September, he homered on his final swing at Busch Stadium to lift the Cards to win over the Nationals. In between, he drove in 21 runs in 24 games and posted an impressive .807 OPS.
Rookie Leo Bernal needed just 24 games to drive in 21 runs in 2026. -- Jeff Le-Imagn Images
3. Quinn Mathews
Mathews had the best season of any Minor League player in 2024 when he rose through four levels and struck out 204 batters. However, he struggled badly in 2025 and never got close to the MLB promotion most expected for him. That call finally came in 2026, and the Stanford University product showed the stage wasn't too big for him. He had three straight starts of at least six innings of work in September and he posted a 3.83 ERA over nine starts. He will be in consideration for a rotation spot in 2026 because of a lethal changeup that certainly played at the big-league level.
Quinn Mathews had three straight starts in September of at least six innings.
4. Joshua Báez
Báez's first season will always be remembered for his destruction of the Cubs in his debut, but he actually showed more of his all-around skills in his 29 games before suffering a season-ending oblique strain. Here is where some of Báez's underlying metrics would have ranked if he had enough at bats to qualify: 77.5 mph bat speed (seventh), 92.1 mph average exit velocity (T-22nd), 47.1 percent hard-hit rate (43rd) and 11.8% barrel rate (56th).
Joshua Báez became the first player in MLB history to homer in his first three at bats on Aug. 15.
5. Luis Gastelum
Using his devastating changeup, Gastelum put himself in position for an MLB call-up with a stellar stretch at Triple-A Memphis. However, the Cardinals were forced to be patient with Gastelum as he learned how to set up MLB hitters and keep them off his changeup. Over his first 10 outings, Gastelum worked 10 innings and pitched to a 6.30 ERA. During that time, he surrendered four homers and foes knocked him around at a .333 clip. However, in Gastelum's next 11 outings, he went 2-1 with a 3.86 ERA while allowing just one homer and 22 strikeouts compared to just two walks.
Luis Gastelum struck out 44 batters in 36 2/3 innings of work as a rookie.
