Red Sox's Sonny Gray replacement has never pitched above Double-A

Puerto Rico pitcher Eduardo Rivera (99) Troy Taormina-Imagn Images

Red Sox's Sonny Gray replacement has never pitched above Double-A

By Zachary Cariola | Last updated Apr 22, 2026 1:44 PM ET

The Boston Red Sox's starting rotation hasn't been great this season, even though they have 2025 American League Cy Young runner-up, left-hander Garrett Crochet, on the staff. The Red Sox starting staff ranks 26th in MLB in ERA (4.94).

As 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 and has since landed on the injured list.

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 provide a spark.

Red Sox call up a prospect who has never pitched above Double-A

According to Red Sox beat writer for MassLive.com Chris Cotillo, the team is calling up left-hander Eduardo Rivera 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.

Per sources, Red Sox will select Eduardo Rivera, option Jack Anderson and clear a 40-man spot by shifting Triston Casas to the 60-day IL today.
— Chris Cotillo (@ChrisCotillo) April 22, 2026

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. He has a 0.90 ERA in two starts this season. Ranked as the Red Sox's 26th-best prospect, Rivera carries a three-pitch mix: a four-seam fastball that can top out at 98 mph, a slider and a changeup.

An imposing force on the mound, standing at 6-foot-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.

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.

The Red Sox will give Rivera a look to see if he's worth keeping around. Gray will likely miss two starts, but once he returns, Rivera could wind up back in Triple-A.

Zachary Cariola

My name is Zachary Cariola and I have been a sports fan for as long as I can remember. My areas of expertise are MLB, NBA, and NFL. When I’m not writing, I love spending time with my family and learning history.

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