Cardinals Have Pitching Prospect With Legit Ace Potential

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If you're a St. Louis Cardinals fan, the top prospect you should know with Spring Training quickly approaching outside of infielder JJ Wetherholt is big lefty Liam Doyle.
Doyle was selected with the No. 5 overall pick in the 2025 Major League Baseball Draft by St. Louis out of the University of Tennessee. Before he was even drafted by the Cardinals, ESPN's Kiley McDaniel graded his fastball 60/65 and noted that it could've gotten big league hitters out at that time.
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"Fastball: 60/65, Cutter: 50/55, Slider: 45/50, Splitter: 45/55, Command: 40/50," McDaniel wrote back in July. "Where he ranks in an MLB top 100 prospects list: 52. If it doesn't work out, what happened? His frame/delivery/approach doesn't allow him to turn over a lineup, so he pitches 60 to 100 inning per year with some impact in a lesser role. Doyle was a second-round follow after last season, then burst onto the scene this spring throwing harder and more strikes and showing crisper off-speed stuff. Scouts still hesitate given the effort of his delivery, his heavy fastball usage, the fact that his stuff can fade a bit late in games and his poor performances down the stretch.
The Cardinals have a few intriguing prospects

"That said, his fastball could probably get big league hitters out right now, and he can throw it in the right part of the zone. His cutter and splitter are both above average, so you could argue that the fastball usage and control (throwing it over the plate) over command (hitting spots) can both be fixed almost immediately."
That was before Doyle came to the organization. He was on the board at No. 5 and the Cardinals snatched him up. Now, he's the team's No. 2 prospect. Don't expect to see him in the big leagues right away in 2026, but he's someone fans should be watching very closely in 2026 overall.
Doyle made just two professional appearances in 2025, but the Cardinals moved him up all the way to Double-A. He made a start with the Double-A Springfield Cardinals and struck out three across two innings of work. A small sample, but the fact that the Cardinals had him in Double-A at all says a lot.
He's 21 years old and is certainly a candidate to shoot through the system quickly if he can impress in 2026. By the time the fall gets here, Doyle is someone who very well could be on the doorstep to the majors. If not, then definitely 2027.
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Patrick McAvoy's experiences include local and national sports coverage at the New England Sports Network with a focus on baseball and basketball. Outside of journalism, Patrick also is pursuing an MBA at Brandeis University. After quickly rising as one of the most productive writers on the site, he expanded his reach to write for Baseball Essential, a national baseball site in Sports Illustrated Media Group. For all business/marketing inquiries regarding Inside The Cardinals, please reach out to Scott Neville: nevilles@merrimack.edu