Cardinals Acquire Left-Hander Eduardo Rivera From Boston

November 4, 2026. St. Louis sent pitching prospect Juan Garcia to Boston for Rivera, who could join the Cardinals’ major-league roster at the start of the 2027 season. Garcia is not close to the majors, while Rivera made his big-league debut in 2026.

Rivera, 23, appeared in four games for Boston, including three starts, and recorded a 6.30 ERA over 10 innings. In Triple-A Worcester, he had a 2.96 ERA in 24 appearances, three of them starts. The brief major-league stint offers a limited basis for judging his performance, while his minor-league numbers offer a more encouraging sign.

At 6-foot-7, Rivera throws left-handed and has a fastball described as blistering. He retains rookie status entering 2027, and St. Louis has team control over him for multiple seasons. The Cardinals could use him in the bullpen, though his ability to carry his Triple-A success into the majors remains to be seen.

St. Louis’ bullpen had a 4.40 ERA in 2026, ranking 20th in the majors, while the team shared the league’s third-highest blown-save total, with 30. The Cardinals finished 77-85 and were 11 games out of the final National League wild-card spot. Rivera’s arrival is an early move to address that weakness ahead of the 2027 season.