Hours after signing Jason Delay to a minor league deal to bolster their catching depth, the Boston Red Sox inked another minor league deal to help shore up their pitching.
Boston has re-signed lefty pitcher Eduardo Rivera to a minor league deal, first reported by Alex Speier of The Boston Globe. Rivera, 22, had previously been a reliever in the Athletics organization, but it released him in May 2024. The Red Sox traded for him shortly after and he's been making his way up the minor league system ever since.
The A's drafted Rivera in the 10th round of the 2021 MLB Draft, and since he hasn't yet appeared in the big leagues, he'll be eligible for Rule 5 Draft selection this winter. In order to protect him from potentially being nabbed by another team, the Red Sox would have to add Rivera to their 40-man roster and keep him there for the rest of the season. This could be a big ask for a team that has over two dozen other players it could protect, including top starting pitching prospect, David Sandlin.
Rivera could be an intriguing Rule 5 pickup for another team after his first full, successful season in the Red Sox organization. He posted a 2.48 ERA with 108 strikeouts and 46 walks between High-A Greenville and Double-A Portland in 2025.
Red Sox re-sign lefty pitching prospect Eduardo Rivera, who could be selected in Rule 5 Draft
6 strikeouts in 5 scoreless innings for Eduardo Rivera. 👊 pic.twitter.com/m3DkyELIO0
— Red Sox Player Development (@RedSoxPlayerDev) May 15, 2025
Rivera hasn't yet reached Triple-A, which could be a deterrent for some teams looking for Rule 5 additions, especially some strapped for 40-man roster spots. Clubs are unlikely to give a long-term roster spot to someone who isn't guaranteed to appear in the majors at some point during the upcoming season, but Rivera could.
Speier expects Rivera to be ready for the big leagues either in the middle of or late in the 2026 season. He throws hard, he carries a 30% strikeout rate and his delivery is exceptionally tough on lefty batters. The Red Sox will lose lefty relievers Steven Matz and Justin Wilson to free agency, and although they'll need additional reinforcements before Rivera is ready for big league action, he could be another left-handed weapon in the late innings.
There's hardly such thing as a bad minor league deal, but if the Sox re-signed Rivera just for him to be taken in the Rule 5 Draft, this one could come close. Hopefully Rivera can stay off other teams' radar long enough to pass by the Rule 5 Draft unselected, as he could help the Sox in the big leagues sooner rather than later.