Nationals righty Joan Adon to make first MLB start on Sunday

The Nationals will promote right-hander Joan Adon before Sunday’s game, manager Davey Martinez told reporters (including Jesse Dougherty of The Washington Post) Saturday night. Adon will make his MLB debut starting Washington’s final game of the season. The 23-year-old is already on the Nats’ 40-man roster, added last November in advance of the Rule 5 draft.

While it might not be a long outing for Adon, he’ll at least get a cup of coffee in The Show to cap off his fourth professional season. An amateur signing out of the Dominican Republic back in 2016, Adon hadn’t even pitched at high-A ball before 2021 but advanced up the ladder with more than 105 combined innings at the high-A (87 IP), Double-A (14 IP), and Triple-A (four IP) levels. Adon has a 26.9% strikeout rate and 8.81% walk rate during his 2021 season, and those decent numbers have translated only to a cumulative 4.97 ERA.

MLB Pipeline rates Adon as the 22nd-best prospect in Washington’s farm system, citing his 60-grade fastball with mid-90s velocity. Even though Adon has worked only as a starting pitcher in 2021, Pipeline’s scouting report feels his future as a starter or as a reliever will depend on whether or not he can get consistent success with at least one other secondary pitch.