As he prepares for his first spring training as a member of the Red Sox organization, it feels like an appropriate time to look back at the winter pitching prospect Eduardo Rivera had.
Rivera, a 21-year-old left-hander, spent the winter on his home island of Puerto Rico. The San Juan native opened the 2024-2025 Liga de Béisbol Profesional Roberto Clemente (LBPRC) regular season with the Cangrejeros de Santurce and was excellent.
In 11 regular-season appearances (seven starts), Rivera posted a 1.15 ERA and 0.95 WHIP with a league-leading 56 strikeouts to 12 walks over 39 innings. He made an additional start for the Cangrejeros in the playoffs — in which he struck out eight across six scoreless frames — before they were eliminated by the Senadores de San Juan on January 12.
Three days after Santurce was knocked out of the semi-finals, Rivera joined the Indios de Mayaguez for their best-of-nine LBPRC championship series matchup against San Juan. The lefty got the starting nod in Games 2 and 6 (the clincher) and picked up where he left off by tossing 10 total innings of shutout ball as Mayaguez was ultimately crowned league champion for the 20th time in franchise history.
As a result of being on the championship-clinching team in the LBPRC, Rivera made Puerto Rico’s roster for the 2025 Caribbean Series in Mexicali, Mexico. He unfortunately struggled in his lone start against the Dominican Republic in round-robin action on February 4, surrendering seven runs (three earned) on six hits, one walk, one hit batsman, and five strikeouts over 2 2/3 innings. The Dominican Republic then defeated Mexico in the final on February 7 to take home its fifth Caribbean Series title.
Regardless of how it ended, it was nonetheless a productive winter for Rivera after what must have been a turbulent 2024 season stateside. The southpaw was released by the Athletics (the organization that originally selected him in the 11th round of the 2021 draft out of high school) last May. He then signed a minor-league contract with the Red Sox in June and made four appearances (one start) in the rookie-level Florida Complex League before joining Low-A Salem in late July.
In six outings (four starts) for Salem, Rivera forged a 1.99 ERA (2.56 FIP) with 30 strikeouts to seven walks over 22 2/3 innings in which opposing hitters batted just .175 against him. Among the 21 Red Sox minor-leaguers who threw at least 20 innings in the Carolina League last year, Rivera ranked first in WHIP (0.93), second in ERA and line-drive rate (16 percent), third in strikeout rate (33.3 percent) and xFIP (2.59), fourth in strikeouts per nine innings (11.91), batting average against, FIP, and groundball rate (54 percent), fifth in walks per nine innings (2.78), sixth in swinging-strike rate (14.7 percent), and seventh in walk rate (7.8 percent), per FanGraphs.
Rivera, who does not turn 22 until June, is currently regarded by SoxProspects.com as the No. 58 prospect in Boston’s farm system after previously being unranked. The imposing 6-foot-7, 237-pound hurler throws from a three-quarters arm slot and incorporates a high leg kick into his delivery. He primarily operates with a 92-95 mph fastball that has reached 97 mph and also mixes in a changeup and slider.
Barring a trade or other surprise move, Rivera is projected by SoxProspects.com to make the jump to High-A Greenville for the start of the 2025 season. Whether he does so as a member of the Drive’s starting rotation or bullpen remains to be seen.
(Picture of Eduardo Rivera: Miguel Rodriguez/Getty Images)
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