The St. Louis Cardinals are preparing to promote promising right-handed pitching prospect Luis Gastelum to the major league roster, although the move is not expected to become official before Tuesday’s doubleheader against the Milwaukee Brewers.
According to Derrick Goold of the St. Louis Post-Dispatch, Gastelum is on his way to join the club, confirming an earlier report from Jeff Jones of the Belleville News-Democrat. However, the Cardinals are still sorting through several roster decisions, meaning the rookie will not be available for the opening game of Tuesday’s twin bill and may not officially join the bullpen until Wednesday, depending on how the doubleheader unfolds.
The Cardinals have remained one of the National League’s stronger teams this season, but their bullpen has consistently been an area of concern. While relievers such as Riley O’Brien, JoJo Romero, George Soriano, and Gordon Graceffo have delivered solid performances, inconsistency throughout the relief corps has left St. Louis with a 4.17 bullpen ERA, ranking 17th in Major League Baseball.
Because of those struggles, speculation has grown in recent weeks that the Cardinals could strengthen their relief staff internally instead of pursuing an expensive trade. Gastelum quickly emerged as the leading candidate for a promotion after putting together an outstanding season at Triple-A.
Ranked as the organization’s No. 21 prospect, the hard-throwing right-hander has dominated hitters with a 2.27 ERA across 36 appearances, consistently demonstrating the command and poise that convinced the Cardinals he was ready for the next level.
Jones first reported Tuesday morning that Gastelum had received the long-awaited call for what will be his Major League debut, noting that the Cardinals would need to clear both a 40-man roster spot and an active roster position before officially adding him.
The timing of the promotion comes as St. Louis has been hit by multiple setbacks in its bullpen.
Left-handed reliever Justin Bruihl suffered a sprained ankle during Monday night’s game against Milwaukee after stumbling while trying to throw out a runner at first base in the seventh inning. His injury is particularly unfortunate because he had recently turned his season around following a difficult start. Bruihl owns a 3.70 ERA in 39 appearances this year, and over his last 15 outings he has been one of the Cardinals’ most reliable relievers, posting an impressive 1.89 ERA across 19 innings.
The Cardinals also announced Monday that right-hander Max Rajcic had been placed on the injured list with a right elbow injury, further depleting an already stretched bullpen.
Those injuries have created an immediate opportunity for Gastelum, who now has the chance to provide much-needed depth while proving he belongs at the highest level.
His rise through the Cardinals’ organization has been remarkably quick. After making his professional debut in 2023, Gastelum steadily climbed the minor league ladder. He had never pitched above Class-A before 2025, but after spending all of last season in Double-A, he earned a promotion to Triple-A in 2026 and continued to impress with his dominant performances.
Now, after months of speculation and strong results, Gastelum is on the verge of realizing his dream of pitching in the major leagues. Although Cardinals fans may have to wait another day before seeing him take the mound, the organization clearly believes the talented right-hander can help stabilize a bullpen that has desperately needed another dependable arm.