Red Sox Designate Young Left-Hander Eduardo Rivera

Boston designated Rivera for assignment as it made roster changes to reach the 40-man limit. The move stood out because the 23-year-old had pitched well in the minors, despite a difficult brief stint in the majors.

Rivera appeared in four major-league games in 2026, making three starts, and recorded a 6.30 ERA. In Triple-A, he posted a 2.96 ERA over 24 appearances, including three starts, and 45 2/3 innings. He also made two Double-A appearances, with a 0.90 ERA.

Listed at 6-foot-7 and 237 pounds, Rivera has a fastball that approaches 100 mph. Boston’s roster decisions came as the club had players to reinstate from the 60-day injured list. The team also designated right-hander Zack Kelly, who was limited by injury and spent part of the season in Triple-A.

Rivera could remain in the organization if no team claims him on waivers; Boston could then assign him outright to the minors. The move leaves 27-year-old Raymond Burgos on the 40-man roster. The Red Sox have already made a trade this offseason, and free-agent signings can now begin.