The St. Louis Cardinals bolstered their bullpen Tuesday by selecting the contract of right-handed reliever Luis Gastelum from Triple-A Memphis. In a corresponding move, the club designated left-hander Jared Shuster for assignment. Gastelum is set to make his Major League debut, becoming the latest reinforcement for a relief corps in search of consistency.
Gastelum, 24, was an international free agent signing out of Mexico in April 2023 after pitching two seasons for Los Mochis in the Mexican League. The 6-foot-1, 185-pound right-hander has been one of the International League’s most reliable arms this season, posting a 7-1 record with a 2.27 ERA across 36 appearances for Memphis. He has locked down three saves while striking out 49 batters in 43 2/3 innings.
What stands out most is his recent dominance. Gastelum has not been scored upon over his last 18 appearances — tied for the longest scoreless streak in the minors this season. That run dates back to May 21 and spans 22 1/3 innings, during which he has posted a 0.58 WHIP, allowing just eight hits and five walks. He has turned in eight appearances of four outs or more during the streak.
The Cardinals originally signed Gastelum for a modest sum, and he has steadily progressed through the system with consistent performances. He had not previously ranked among the organization’s top 30 prospects entering the year, but his breakout 2026 campaign has elevated him to No. 21 on MLB Pipeline’s Cardinals prospect list and No. 25 by Baseball America. Over his professional career, he owns a 17-10 record with a 3.33 ERA, 1.14 WHIP, and an impressive 11.76 strikeouts per nine innings.
Gastelum profiles as a versatile bullpen option. While not overpowering with his fastball and sinker (sitting around 94 mph), his changeup has earned praise as a plus pitch capable of generating swings and misses. He also induces ground balls at a solid rate, adding another weapon for high-leverage situations.
When he takes the mound for the first time, Gastelum will become the seventh Cardinals player to make his Major League debut this season and the fourth pitcher, joining right-handers Matt Pushard and Max Rajcic and left-hander Brycen Mautz. Hailing from Ahome, Mexico, he will be the 17th Mexican-born player in St. Louis Cardinals history and the first Mexican-born pitcher to appear in a game for the club since Giovanny Gallegos in 2024. He will wear uniform No. 72.
The promotion arrives at a critical juncture for the Cardinals, who have dealt with bullpen inconsistencies throughout the season. Gastelum’s plus stuff and recent unhittable form provide manager Oliver Marmol with a fresh, high-upside arm as the team navigates a competitive stretch.
For a franchise that values homegrown talent and internal solutions, Gastelum’s call-up represents another step in the development pipeline. Cardinals fans will be eager to see if the right-hander can carry his minor league success into the majors and carve out a lasting role in the St. Louis bullpen. Updates on his debut and usage will follow as the club faces the Milwaukee Brewers in Tuesday’s doubleheader.
