San Francisco Giants pitching prospect Melvin Adon left a winter league game in the Dominican with an apparent arm injury.

As of yet, there is no news on the type of or severity of the injury.

Adon, 26, has been a mainstay of the Giants top prospect lists since his signing as an international free agent in February of 2015.  His inability to progress has caused those statuses to drop, as he is currently not on Baseball America’s top 30 Giants prospect lists, although he is still ranked as the Giants #24 prospect by MLB Pipeline.  Even so, Baseball America still names him as the Giants’ best fastball.

Adon’s fastball gets up to 102 MPH, although his four-seam fastball has become less-used as he uses his two-seamer more for more movement.  He also has a high-80’s slider that he pairs that with.

The Giants continued to push Adon as a starter through 2018, at which point he posted a 4.87 ERA in a health-limited season at High-A San Jose.  He has since been shifted to relief, and in 2019, he had a 2.60 ERA in 36 games at Double-A Richmond, but once again struggled after a promotion to Triple-A Sacramento, where he had a 13.94 ERA in 12 appearances.  Combined, Adon had 77 strikeouts in 55.1 innings, but also had 34 walks.

Adon did not appear with the Giants in 2020, but was added to the 60-man player pool in late August, relatively late in the shortened season.

Adon’s struggle to limit walks has undermined his progress, and has walked 161 in 373.1 innings in his minor league career, a rate of 3.88 BB/9 IP.  He has also struggled to stay healthy, as his season high in innings was 99.1 in 2017 with Augusta.