Cardinals claim lefty Luis Peralta, option him to Triple-A Memphis

The Cardinals used an open 40-man roster spot to claim left-hander Luis Peralta from the Rockies on April 27, then optioned him to Triple-A Memphis, a move that added another left-handed relief arm to the organization without forcing a corresponding roster cut. For a club that has already shown a willingness to churn through waiver-wire bullpen help, Peralta is less a lottery ticket than a test case: can St. Louis clean up enough of his command and consistency to make him useful in the majors again?

Peralta, 25, is a left-handed pitcher who bats and throws left and was born Jan. 6, 2001, in Moca, Dominican Republic. He made his big-league debut on Aug. 24, 2024, at Yankee Stadium and has logged 37 career MLB games, 31.1 innings, 30 strikeouts and 23 walks, with a 6.03 ERA and 1.79 WHIP. The surface numbers have been rough, but his profile is still that of a live lefty, and that matters in a bullpen market where clubs keep looking for cheap, optionable arms who can be moved between Triple-A and the majors.

Colorado designated Peralta for assignment on April 15 after recently cycling him through its own roster traffic, including a Triple-A stop with Albuquerque. Before the Cardinals claimed him, he had struggled badly at Triple-A in 2026, allowing 14 runs with a 14:13 strikeout-to-walk ratio over 7.1 innings for the Isotopes. That uneven form helps explain why he was available, but it also shows why St. Louis could see a buy-low opportunity: the lefty has already shown he can survive in the majors in short bursts, even if the results have swung wildly from outing to outing.

His 2025 season for Colorado underscored that volatility. MLB’s player page lists a 9.47 ERA across 22 appearances, but he did not allow an earned run in 13 of those outings. At Coors Field, though, he was hit hard, posting a 16.88 ERA in 11 home appearances. He also picked up his first career win on March 29 at Tampa Bay, a reminder that the arsenal has been good enough at times to get big-league outs.

Peralta is also the younger brother of Brewers ace Freddy Peralta, another detail that adds to the scouting intrigue. For Memphis, he joins a left-handed relief pipeline that has already been asked to absorb turnover, and for St. Louis the timeline is simple: if Peralta throws strikes at Triple-A, he could become major-league relevant quickly, because the path back is already built in by the open roster spot and his remaining option flexibility. Earlier in the offseason, the Cardinals made a similar bet when they claimed lefty Bailey Horn, and Peralta fits the same pattern of searching for usable innings before a bullpen emergency forces the issue.