The Twins on Wednesday acquired a 21-year-old righthander from Washington in exchange for reliever Ryne Harper, the team announced.

Hunter McMahon, who posted an 0.71 ERA in his first 12 innings of professional baseball last summer, was traded by Washington to the Twins in exchange for Harper, the 30-year-old rookie who made the team with a strong spring training in 2019.

Harper was designated for assignment last week in order to clear a roster spot for third baseman Josh Donaldson. Harper compiled a 3.81 ERA in 61 relief appearances for the Twins last season.

McMahon, drafted in the ninth round by the Nationals in the 2019 draft, made nine appearances, all in relief, for the Nationals' Gulf Coast League rookie team and Class A Auburn after signing. He struck out 23 batters and walked five in 12 total innings, and allowed an earned run only once.