The Red Sox are promoting left-hander Eduardo Rivera, as first reported by Javier Sabath. The Sox will option righty Jack Anderson to Triple-A Worcester, according to Ari Alexander of Boston 7 News. They’ll also need to open a spot on the 40-man roster. Triston Casas stands as a 60-day injured list candidate after suffering an intercostal strain on top of his work back from knee surgery.
Rivera makes the jump directly from Double-A Portland. The 22-year-old southpaw dominated over his first two starts of the season. He recorded 16 strikeouts against three walks over 10 innings of one-run ball. Rivera also missed bats for his native Puerto Rico during the World Baseball Classic. He fanned nine hitters over 6 2/3 frames in two WBC games. Rivera allowed three runs on two hits, four walks, and a hit batter.
Listed at 6’7″ and 237 pounds, Rivera cuts an imposing figure on the mound. The long limbs have also contributed to strike-throwing issues in his minor league career. Rivera was an 11th-round selection by the Athletics in 2021. He never advanced out of A-ball in their system and was released in May ’24.
The Red Sox took a flier on his size and a fastball that runs into the mid-90s. They’ve been rewarded for the pickup, as Rivera has pitched well since joining the Boston organization. He combined for a 2.48 ERA while striking out 29.7% of batters faced over 87 innings between High-A and Double-A last season. That came with a near-13% walk rate, but Rivera has been around the strike zone over his first couple appearances this year.
Rivera did not crack Baseball America’s Top 30 prospects. However, MLB Pipeline slotted him #26 in the system with praise for his fastball-slider combination. Rivera probably projects to a bullpen role but is stretched out enough to work multiple innings.
The Red Sox used seven relievers to get through Monday’s game. Their leverage arms got a rest today, as the duo of Anderson and Tyler Samaniego finished the 4-0 loss to the Yankees. Rivera will replace Anderson as a potential mop-up arm. They’re carrying a ninth reliever for the next couple days after placing Sonny Gray on the injured list but will need to drop back to an eight-man bullpen to call up a starter (most likely Payton Tolle) this weekend.