Red Sox pitching prospects Jack Anderson, Eduardo Rivera selected for World Baseball Classic

Red Sox pitching prospects Jack Anderson and Eduardo Rivera were named to Great Britain’s and Puerto Rico’s initial rosters on Thursday for the upcoming World Baseball Classic.

Neither Anderson, a 26-year-old right-hander, nor Rivera, a 22-year-old left-hander, is on Boston’s 40-man roster. Both hurlers joined the organization at different points in 2024, as the former was taken in the minor league phase of that December’s Rule 5 Draft and the latter signed as a minor league free agent six months prior.

Anderson, a former 2021 16th-round draft selection of the Tigers coming out of Florida State, spent most of last season with Double-A Portland. The righty put up solid numbers for the Sea Dogs, posting a 3.58 ERA with 90 strikeouts to 18 walks over 23 outings (four starts) spanning 75 1/3 innings in which opponents batted .244 against him. He also made three starts (one in April, two in September) for Triple-A Worcester but surrendered 14 earned runs in 11 1/3 innings there.

Overall, Anderson forged a 4.57 ERA (3.55 FIP) with 101 strikeouts to 22 walks in 26 total appearances (seven starts) spanning a career-high 86 2/3 innings between Portland and Worcester last year. The 6-foot-3, 197-pounder features a lower-90s four-seam fastball as well as a slider, splitter, cutter, and curveball. He is not currently ranked among the top pitching prospects in Boston’s system by SoxProspects.com.

Rivera, meanwhile, is a former 2021 11th-round draft selection of the Athletics out of Colegio Cadest in Puerto Rico. The San Juan native was released by Oakland in May 2024 and signed a minor league contract with the Red Sox a month later. After splitting the remainder of the season between the Florida Complex League and Low-A Salem, Rivera impressed in winter ball and broke camp with High-A Greenville last spring.

To begin his first full season in the organization, Rivera posted a 1.61 ERA with 68 strikeouts to 16 walks over 10 outings (six starts) and 44 2/3 innings for the Drive before receiving a promotion to Portland in late June. Though he experienced some growing pains along the way, Rivera managed a 3.40 ERA with 40 strikeouts to 30 walks in 10 appearances (nine starts) and 42 1/3 innings for the Sea Dogs. Opposing hitters in the Eastern League batted .214 against him.

Altogether, Rivera produced a 2.48 ERA (3.22 FIP) with 108 strikeouts to 46 walks in 20 outings (15 starts) spanning a career-high 87 innings between Greenville and Portland in 2025. The 6-foot-7, 237-pound southpaw can reach 98 mph with his upper-90s fastball and also operates with a cutter, slider, changeup, and curveball. He is currently ranked by SoxProspects.com as the No. 42 prospect in Boston’s system after being brought back on a minor league contract in October.

Rivera, unsurprisingly, spent his offseason once again pitching in winter ball. He helped the Cangrejeros de Santurce win its 17th LBPRC title last month and, as a result, is now representing Puerto Rico in the Caribbean Series, which runs through February 7 down in Mexico.

Assuming they get through next month’s World Baseball Classic unscathed, both Anderson and Rivera are projected by SoxProspects.com to return to Portland for the start of the 2026 season.

(Picture of Jack Anderson: Maddie Malhotra/Boston Red Sox/Getty Images)

Red Sox promote Rule 5 addition Jack Anderson to Triple-A Worcester

The Red Sox promoted right-hander Jack Anderson from Double-A Portland to Triple-A Worcester on Friday, as was first reported by Beyond the Monster’s Andrew Parker.

Anderson opened his first season in the Red Sox organization with Portland as a member of the Sea Dogs’ bullpen. The 25-year-old appeared in two games for Boston’s Eastern League affiliate out of the gate, allowing one unearned run on four hits, zero walks, and 10 strikeouts over 4 2/3 innings of relief.

A former 16th-round draft pick of the Tigers coming out of Florida State in 2021, Anderson switched organizations for the first time in his professional career over the winter when the Red Sox plucked him in the minor-league phase of December’s Rule 5 Draft.

Anderson appeared in three Grapefruit League games for Boston as a minor-league call-up this spring, yielding two earned runs on seven hits, one walk, and five strikeouts over 3 1/3 innings. He also retired the lone batter he faced (former Red Sox farmhand Esteban Quiroz) in the club’s exhibition finale against the Sultanes de Monterrey in Mexico on March 25.

In that particular outing, which only required five pitches (four strikes), Anderson threw three four-seam fastballs, one cutter, and one slider, per Baseball Savant. Throwing from a three-quarters arm slot, the 6-foot-3, 197-pound righty reached 91.6 mph with his heater, 84.6 mph with his cutter, and 80.1 mph with his slider.

Anderson, who does not turn 26 until November, has previous experience at the Triple-A level. The Florida native appeared in eight games (made one start) for Detroit’s top affiliate last season and posted a 5.82 ERA (4.98 FIP) with 10 strikeouts to six walks over 17 innings with the Toledo Mud Hens.

With the WooSox, Anderson seems likely to join a righty-heavy bullpen mix that consists of Luis Guerrero (on the 40-man roster), Bryan Mata, Nick Burdi, Isaiah Campbell, Jose Adames, Wyatt Mills, Jacob Webb, and lefty Brendan Cellucci. Hobie Harris, who was also taken in the minor-league phase of December’s Rule 5 Draft, is currently on Worcester’s 7-day injured list with right shoulder inflammation.

(Picture of Jack Anderson: Maddie Malhotra/Boston Red Sox/Getty Images)