Michael Andrew Alvarez (born June 13, 1999) is an American professional baseball pitcher for the Washington Nationals, who made his MLB debut in 2025. After playing college ball at Cal Poly, he was drafted by the Nationals in the 12th round of the 2021 MLB draft and steadily climbed the minor league ranks, earning the team's Minor League Pitcher of the Year award in 2023 with a 2.99 ERA. He was promoted to the majors on September 1, 2025, and delivered a stellar debut, pitching five scoreless innings against the Miami Marlins to secure a 2–0 victory—becoming only the second Nationals starter in 15 years to win his debut. That same game was also the MLB debut for his catcher, C. J. Stubbs, making them the first batterymates to debut together since 2023 and the first for the Nationals since 2008. Despite his strong start, Alvarez was optioned to Triple-A Rochester to begin the 2026 season.