Joan Manuel Adon (born August 12, 1998) is a Dominican professional baseball pitcher for the Caliente de Durango of the Mexican League. He has previously played in Major League Baseball (MLB) for the Washington Nationals.
Adon signed with the Washington Nationals as an international free agent on July 2, 2016. He started his professional career with the Dominican Summer League Nationals in 2017. Adon split the 2018s season between the rookieâÂÂlevel Gulf Coast League Nationals and the LowâÂÂA Auburn Doubledays, going a combined 3âÂÂ1 with a 4.11 ERA and 40 strikeouts over innings. He spent the 2019 season with the SingleâÂÂA Hagerstown Suns, going 11âÂÂ3 with a 3.86 ERA and 90 strikeouts over 105 innings. In 2020, he was named to Washington's 60-man player pool, working out at the alternate training site in Fredericksburg, Virginia, during the coronavirus-shortened MLB season. On November 20, 2020, the Nationals added Adon to their 40-man roster to protect him from the Rule 5 draft.
Adon split the 2021 minor league season between the HighâÂÂA Wilmington Blue Rocks, the DoubleâÂÂA Harrisburg Senators, and the TripleâÂÂA Rochester Red Wings, going a combined 7âÂÂ6 with a 4.97 ERA and 122 strikeouts over 105 innings.
On October 3, 2021, Adon was promoted to the active roster to make his MLB debut against the Boston Red Sox. He pitched into the sixth inning, striking out nine, while giving up two earned runs: a fourth-inning solo homer by Rafael Devers, then a runner bequeathed to reliever Patrick Murphy who came around to score in the sixth. His nine strikeouts were the most by a pitcher making his MLB debut in the 2021 season.
Adon made the rotation to begin the 2022 season, despite only having made five starts above the HighâÂÂA level. Adon was the first pitcher to record his 10th loss during the season, which happened on June 7 after a start against the Miami Marlins in which he yielded 8 runs in 3 innings pitched, his worst start of the season. After the game, he was optioned to Triple-A Rochester, as Stephen Strasburg came off the injured list on June 9 to take his place in the rotation. At the time, Adon was 1âÂÂ10 with a 6.95 ERA and 1.76 WHIP in 12 starts, walking 5.66 batters per 9 innings, all league-worst totals among pitchers with at least 50 innings pitched. In addition, his whiff rate was the lowest in the major leagues, as batters made contact on 86.6% of their swings. His one win, his first in the major leagues, came in a start against the Arizona Diamondbacks on April 19, in which he threw scoreless innings. Adon was brought back up to the major leagues to start the first game of a double-header against the Philadelphia Phillies on June 17, but after recording his 11th loss, Adon was sent back down to Triple-A the following day.
Adon was optioned to TripleâÂÂA Rochester to begin the 2024 season. In 8 games for Washington, he struggled to a 6.75 ERA with 6 strikeouts over innings pitched. On August 28, 2024, Adon was placed on the injured list with a right biceps strain. He was transferred to the 60âÂÂday injured list on September 20, ending his season.
Adon was designated for assignment on January 8, 2025. He cleared waivers and was sent outright to Rochester on January 15. In 34 appearances for the Red Wings, Adon logged a 2-2 record and 5.70 ERA with 46 strikeouts across innings pitched. He elected free agency following the season on November 6.
On March 4, 2026, Adon signed with the Caliente de Durango of the Mexican League.
Adon pitches with a fastball that averaged about in his 2019 campaign with the Class-A Hagerstown Suns, as well as a slider and changeup, although his changeup was used sparingly at the time of his demotion from the big leagues in June 2022.