This Cardinals prospect is on fast track

This story was excerpted from John Denton’s Cardinals Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

At a rail-thin 188 pounds, Quinn Mathews isn’t exactly an imposing figure when he takes the mound for the Peoria Chiefs, the Cardinals' High-A affiliate. The intimidating part comes when the lanky Mathews unleashes a four-seam fastball that has reached as high as 97 mph this spring while he's pitched exceptionally well for two classifications of teams thus far.

Before the 2024 season is complete, that electrifying fastball and Mathews' distinct upward trajectory could potentially allow the talented left-hander and St. Louis' No. 21 prospect to zip through all four levels of the Cardinals' Minor League clubs and reach the doorstep of the big leagues.

The Cards selected the 6-foot-5 Mathews in the fourth round of the 2023 MLB Draft (No. 122 overall), but they decided to rest him over the remainder of last season after he pitched Stanford University into the NCAA World Series.

Famously -- or infamously, depending on your point of view -- Mathews threw a staggering 156 pitches while striking out 16 in Stanford's win over Texas last spring. It was a part of a season in which he was the Pac-12 Pitcher of the Year after striking out the second-most batters in Stanford history (158).

Unlike in the past when St. Louis has aggressively slotted in prospects at higher levels, the club had Mathews start his professional career at Single-A Palm Beach this spring. That experiment proved to be a short one after Mathews used his overpowering fastball to completely overwhelm Single-A hitters.

In his first six starts with the birds on a bat splattered across his chest, Mathews struck out 52 hitters in just 30 2/3 innings. His K rate was even more impressive when considering that he walked just 11 batters.

In his second pro start, Mathews struck out 11 Daytona Beach hitters while surrendering just one hit and zero walks over five innings. Two weeks later, he proved that he was ready for a higher quality of hitters by whiffing 13 Fort Myers hitters in six innings of scoreless work.

That kind of dominance earned the Aliso Niguel, Calif., native a promotion to High-A Peoria, where his strong strikeout stuff continued to play at a high level.

In Mathews first start with the Chiefs on Friday, he mowed through the Western Michigan Whitecaps as such: 11 strikeouts, three hits, one run and one walk over seven innings of easy, breezy work.

Mixing his four-seam fastball, two-seam sinker, curveball and sweeper/slider beautifully, Mathews has been almost untouchable thus far -- especially when facing left-handed hitters. He posted an eye-popping 41 percent K rate versus lefty hitters (16 K's vs. 39 batters) while pitching for Palm Beach.

In his first start for Peoria, he logged strikeouts in three of the four at-bats by left-handers.

If he keeps that sort of dominance up, Mathews could find himself pitching at Double-A Springfield before temperatures even threaten 95 degrees in the Midwest.

Mathews' “wow” weapons have been an electrifying fastball he hasn’t been afraid to throw up in the zone and effective offspeed pitches that have kept foes off his heat. While pitching for Palm Beach, Mathews threw four-seam fastballs 39.9 percent of the time, and he used that pitch to rack up 14 strikeouts (four of them looking). He showed off his arm strength by hitting 97.3 mph, 96.8 mph, 96.7 mph and 96.3 mph on strikeout pitches, per Baseball Savant.

To illustrate just how complete a pitcher Mathews has been thus far, he has 16 strikeouts with his fastballs, 13 on offspeed pitches and 11 with a sweeper/slider mix.

Considering their dearth of pitching prospects at Triple-A Memphis -- see the club’s enormous struggles filling their No. 5 starter spot at the big league level after lefty Steven Matz went down with a back injury -- expect the Cardinals to be especially aggressive in promoting Mathews through their system in the coming months if he continues to dominate foes.