The Boston Red Sox’s starting rotation has not been great this season, even though they have the runner-up in the 2025 American League Cy Young Award voting, left-hander Garrett Crochet, on the staff. The Red Sox starting staff ranks 26th in baseball in ERA (4.94).
If things couldn’t get any worse for the Red Sox, right-hander Sonny Gray left his start on Monday with a right hamstring strain. With Gray down and things not going the Red Sox’s way through 23 games (9-14), they are calling up one of their top prospects to fill in and give them a spark.
The Red Sox call up a prospect who has never pitched above Double-A
According to Red Sox beat writer for MassLive.com Chris Cotillo, left-hander Eduardo Rivera has been called up to replace Gray. To clear a space for Rivera on the active and 40-man rosters, the Red Sox optioned right-hander Jack Anderson to Triple-A Worcester and transferred first baseman Triston Casas (ruptured left patellar tendon/left abdominal strain) to the 60-day injured list.
Rivera, 22, has never pitched above Double-A in his professional career but was a part of Team Puerto Rico in this spring’s World Baseball Classic, and had a 0.90 ERA in two starts this season. Ranked as the Red Sox’s 26th prospect, Rivera carries a three-pitch mix: a four-seam fastball that can top out at 98mph, a slider and a changeup.
An imposing force on the mound, standing at 6-7, Rivera was impressive between Single-A and Double-A last season. In 20 games (15 starts), Rivera went 4-6 with a 2.48 ERA and a career-high 108 strikeouts.
A native of Puerto Rico, Rivera is known for pounding the strike zone, posting a 62% career strike percentage and a 10.99 career strikeout per nine innings. Rivera is coming off a dominant start on April 16 against the Altoona Curves, where he struck out nine and walked two in 5.2 innings.