For the St. Louis Cardinals to take the next step in their rebuild, they need to identify who will be in the starting rotation in the long term.

Michael McGreevy, Kyle Leahy, Andre Pallante and even Quinn Mathews all gave themselves a shot in 2026. But the Cardinals need more. If you look at the two teams in the World Series (Tampa Bay Rays and the Milwaukee Brewers), you'll see franchises who with elite pitching that have grown from within and then added when necessary. The Cardinals' lineup is pretty good, but the rotation isn't quite up to the level to contend yet. That could change in the not-so-distant future. There is so much talent at the top of the farm system. If St. Louis hits on even just a few of its top pitching prospects, the calculus will change.

This idea starts with Liam Doyle. The big lefty was selected with the No. 5 overall pick in the 2025 MLB Draft and spent the 2026 season in Double-A. So, when could he help the big league club? Roundtable Sports' John Denton noted that he "almost assuredly" will get an invite to Spring Training and then if he plays his cards right, as early as June or July of 2027 could be a time in which we see Doyle in the majors.

Liam Doyle Is Going To Be A Star

"He almost assuredly will get an invite to Spring Training with the Cardinals and start the season with Triple-A Memphis — similar to No. 1 prospect Rainiel Rodriguez," Denton wrote. "A strong start could land him in St. Louis by June or July if all goes well with his progression. There will be a learning curve with Doyle and his ability to handle his emotions against MLB hitters, but he appears to be on a collision course with stardom because of his overpowering fastball and oozing confidence."

In 2026, Doyle flashed his star potential with Double-A Springfield. He finished the season with a 3.76 ERA in 23 starts to go along with a 130-to-54 strikeout-to-walk ratio in 103 innings pitched. The overall numbers don't tell the entire story, though. Doyle was working on his secondary pitches in game action early on in the 2026 season. Naturally, that led to some struggles as he worked through things.

He got better and better as the season progressed, though. From June 26 through Sep. 23, Doyle logged a 1.68 ERA and an 80-to-34 strikeout-to-walk ratio in 64 1/3 innings pitched in 13 outings. In his final 13 starts of the season, he never allowed more than two runs in a game. In comparison, Doyle had a 5.54 ERA in his first 10 starts of the season.

As Doyle got more comfortable on the hill, he dominated. If that trend continues into Spring Training and the 2027 season, he very well could be someone who takes the Cardinals' rotation to a higher level. He doesn't just have middle-of-the-rotation potential. Doyle has the upside to be an ace in the majors, which the Cardinals need.