The St. Louis Cardinals made some changes to their bullpen ahead of their doubleheader against the Milwaukee Brewers on Tuesday.As St. Louis got ready for the doubleheader as part of its five-game series with Milwaukee, the team made multiple roster changes with its bullpen, including calling up 31-year-old reliever Bruce Zimmermann along with Hunter Dobbins.The Cardinals quickly put Zimmermann to work, utilizing the veteran reliever in a long-relief role in the first game of the doubleheader. In his first appearance of the season, Zimmermann allowed three earned runs on six hits with two strikeouts across five innings. Surprisingly, Zimmermann's appearance will be his only one with the Cardinals, as the team announced they were designating the 31-year-old for assignment after the first game of their doubleheader and calling up Jared Shuster. Cardinals DFA Zimmermann, call up Jared ShusterJul 7, 2026; St. Louis, Missouri, USA; St. Louis Cardinals pitcher Bruce Zimmermann (54) pitches against the Milwaukee Brewers during the fourth inning at Busch Stadium. Mandatory Credit: Jeff Curry-Imagn Images | IMAGN IMAGES via Reuters ConnectZimmermann earned his opportunity with the Cardinals after performing well in Triple-A this season, posting a 3.78 ERA in 78 2/3 innings across 15 starts. The 31-year-old spent the first four seasons of his big-league career with the Baltimore Orioles, but most recently played with the Brewers in 2025 before joining the Cardinals.In Zimmermann's place, the Cardinals called Shuster up to the big leagues. The 27-year-old signed a minor league contract with St. Louis this offseason and had made four earlier appearances this season, posting a 2.35 ERA across 7 2/3 innings. Shuster did not fare as well against the Brewers. The left-handed reliever allowed seven earned runs on five hits with three walks in just 1 1/3 innings, continuing the Cardinals' pattern of bullpen struggles.As St. Louis' bullpen has struggled this season, the team has continued to search for production, calling up multiple players from its farm system. In addition to giving Zimmermann an opportunity, the Cardinals finally seem to be giving one of their pitching prospects, Luis Gastelum, a chance as well. It seems the Cardinals did not intend to keep Zimmermann on their roster after the one outing in the doubleheader, and with no minor league options remaining, the veteran hurler will be on waivers after being designated for assignment. There is still a chance that St. Louis could retain the 31-year-old reliever if he clears waivers, but it will be interesting to see if he goes unclaimed. Bottom line is that the Cardinals need more production from their bullpen.More MLB: Cardinals' Ivan Herrera Shares Creative Way He Prepared To Face Jacob MisiorowskiAdd us as a preferred source on GoogleFollow