The St. Louis Cardinals are calling up left-handed starter Brycen Mautz to make his MLB debut against the Cincinnati Reds. Derick Goold reports.
Mautz, 24, is St. Louis’ 20th-ranked prospect according to MLB Pipeline. This season, Mautz has a shiny 2.90 ERA through his first nine starts. And that’s after a stellar 2025 where he posted a sub-3.00 ERA in over 114 innings of work.
According to MLB Pipeline, Mautz “throws from a low three-quarters slot that gives him a little deception and a flat angle on his fastball.” His ability to deceive hitters upticks the quality of his pitch-mix across the board. In addition to sneaky stuff, Mautz can throw an occasional chair. Last season, the southpaw struck out over ten batters per nine and is hovering around the same mark this season. With his debut, he’ll immediately become the Cardinals’ best swing-and-miss pitcher in the starting rotation.
After an incredible debut for recent call-up Bryan Torres, The Lou is excited about another new Cardinal.
MLB World Reacts to Brycen Mautz Call Up
Birds on the Farm: “Brycen Mautz is getting his call to the big leagues! Check out our interview with him on Birds on the Farm!”
Redbird Farmhands: “Brycen Mautz gets the call to make his debut. A 2.90 ERA across 9 starts this year with 43 strikeouts and 24 walks across 40.1 innings. After walking 16.7% of batters his first 5 starts he’s dropped that down to 9.8% in his last 4 starts as he gets used to the MLB ball.”
Ray Mileur: “Brycen Mautz isn’t just getting a spot start Sunday — he has earned this look. The 24-year-old lefty was the #STLCards 2025 Minor League Pitcher of the Year after helping lead Springfield to a Texas League title, then carried that momentum to Memphis with a 2.90 ERA over 40.1 innings this season. From college walk-on to second-round pick to 40-man roster arm, now comes the next step.”
Derick Goold: “Brycen Mautz will start for #stlcards on Sunday in the series finale against the #Reds. It will be his major-league debut.”
STL Sports Central: “The #STLCards are promoting their No. 20 prospect, LHP Brycen Mautz, per @dgoold. He will start on Sunday. Tomorrow’s scheduled starter, Liberatore, will now start Monday in Milwaukee — all starters get an extra rest day Mautz is pitching to a 2.90 ERA and 1.36 WHIP in 9 AAA starts this year.”
Jeff Jones: “Cardinals are shifting their pitching plans. Brycen Mautz starts here tomorrow, making his MLB debut.”
Cardinals Pitching Right Now
The St. Louis rotation has been rather mediocre outside of an outstanding start from Michael McGreevy. Unfortunately, the numbers say he may be subject to some regression.
Offseason acquisition Dustin May has been much better recently, but still holds an ERA of 5.00.
The rest of the rotation, although better than expected, hasn’t been special. Cumulative numbers this month have been successful, but individual performances and isolated stuff point towards a fall from grace.
Mautz might be inexperienced, but he’s got the stuff. The Cardinals’ 2025 Minor League Pitcher of the Year will get his shot tomorrow in the series finale against Cincinnati.
Cardinals Promoting Surging Southpaw for MLB Debut Vs. Reds