Red Sox sign former Giants pitching prospect Melvin Adón to minor-league deal

The Red Sox signed former Giants pitching prospect Melvin Adon to a minor-league contract last week, according to the club’s MLB.com transactions log. It is unclear if the deal comes with an invite to major-league spring training.

Adon, 29, spent the last nine seasons in the Giants organization before reaching free agency this past November. The Dominican Republic native originally signed with San Francisco for $50,000 as a 20-year-old international free agent coming out of Santo Domingo in February 2015.

Making his professional debut in the Dominican Summer League later that year, Adon quickly emerged as one of the more intriguing arms in San Francisco’s farm system. The right-hander worked his way up through the organization primarily as a starter, but successfully transitioned to the bullpen in the 2018 Arizona Fall League before being added to the Giants’ 40-man roster that November in order to receive protection from the Rule 5 Draft.

Adon was ranked by Baseball America as the Giants’ No. 12 prospect to open the 2019 season. Used exclusively as a reliever that year, he forged a 4.72 ERA with 77 strikeout to 34 walks in 48 appearances (55 1/3 innings) between Double-A Richmond and Triple-A Sacramento. Adon did not pitch for a minor-league affiliate in 2020 as a result of the COVID-19 pandemic, but he wound up injuring himself in winter ball that offseason and underwent right shoulder surgery in February 2021 as a result.

The procedure cost Adon, who was non-tendered by the Giants and brought back on a minor-league deal, all of 2021 and the first two months of the 2022 campaign. He returned to action in the rookie-level Arizona Complex League that June and closed out the year in Richmond.

Adon was at spring training with the Giants around this time last year. He pitched at three different levels during the 2023 season, though 32 of his 43 appearances came with Sacramento. In two separate stints with the River Cats, the righty posted a 7.43 ERA (5.90 FIP) with 50 strikeouts to 37 walks over 40 innings of relief in which opponents batted .297 against him.