Only two prospects ranked inside their clubs' Top 30 lists by MLB Pipeline have a full 80-grade arm in the field, the highest rating available on the scouting scale. One of them is shortstop Masyn Winn, and he’s bringing that cannon to St. Louis, where he will join the Major League roster Friday.

Winn has steadily climbed through the Cardinals’ system since he was selected with the 54th overall pick in the 2020 Draft, but his prospect stock reached a fever pitch when he ripped off a 100.5 mph throw on an infield assist from shortstop during the 2022 SiriusXM All-Star Futures Game. (Elly De La Cruz, who debuted earlier this season for the Reds, set the all-time Major League mark for an infield assist at 99.8 mph.)

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But while his throwing arm is his flashiest and most impactful tool, things have clicked offensively for Winn with Triple-A Memphis this summer. In 22 July contests, the Cardinals’ top-ranked prospect amassed 18 extra-base hits and 26 RBIs, slashing .359/.427/.750 en route to International League Player of the Month honors. His 97 runs scored are far and away the most of any player at Triple-A and his 128 hits put him just off the pace at the top of the level. Only 21 years old, he faced older hurlers in all but two of 445 Triple-A at-bats prior to his callup.

For most of the 2023 campaign, Winn continued to gain seasoning with Memphis while Paul DeJong primarily held down shortstop duties in St. Louis. But once DeJong was dealt to Toronto at the Trade Deadline and Brendan Donovan (right flexor strain) was ruled out for the remainder of the year, the combination of Winn’s hot stretch and the Cardinals’ opening in the middle infield created room for him in the lineup. Three-quarters of Winn's starts this year have come at shortstop, but since he's also seen significant time at the keystone, he could immediately get playing time at either spot.

Winn impressed in Grapefruit League action during Spring Training, turning heads with his play on both sides of the ball. While he admitted in March that he could “go 50-for-50 with 50 bombs in my next 50 at-bats” and still be positionally blocked on the big league roster, many of those same hurdles no longer exist. He never got that 50-AB homer stretch, but he did deliver his first multihomer game as a pro in May and 11 of his 18 Triple-A long balls came off pitchers with big league experience.

And about that arm ... Winn originally captivated talent evaluators as a prepster from Kingswood (Texas) HS, having ripped off a 98 mph heater on the mound. Ahead of the 2020 Draft, MLB Pipeline graded out Winn’s fastball and curveball as above-average offerings. When the Cardinals selected him in the second round, it was as a two-way player.

Winn’s days as a pitcher are past him after his bat made considerable jumps from year to year in pro ball. (He threw one inning of scoreless relief for High-A Peoria in 2021.) Whereas he once sported raw power at the lower levels, MLB’s No. 32 overall prospect has found a way to tap into it as he has matured. His 18 homers for the Redbirds this season represented a career high and his 211 total bases rank fourth in the International League.

Winn has averaged a 30 ft/sec sprint speed this season at Triple-A, reaching the elite threshold. For context, only 11 players at the Major League level have averaged at or above that number in 2023. While using his plus wheels defensively only adds to his mystique with the glove, he also swiped 92 bags in the Minors while being caught just 12 times, including a 43-steal campaign across two levels last year.

Winn’s arrival marks the latest step taken by an exciting crop of young Cardinals talent, with former No. 1 overall prospect Jordan Walker finding an everyday role this year. Walker and Winn are close friends, having played together both in the Minors and during the 2022 iteration of the Arizona Fall League, where both impressed. Winn has used Walker’s bat in the past, and earlier this year, the duo homered in the same game for Memphis, flashing the tantalizing upside of a lineup when the organization’s top two picks from the 2020 Draft are simultaneously locked in.