Off to a hot start to his major league career, prized New York Yankees prospect Jasson Dominguez has been diagnosed with a torn right ulnar collateral ligament, manager Aaron Boone told reporters Sunday.

Dominguez, 20, may need to undergo Tommy John surgery but no procedure has been scheduled. Position players have returned within six months of surgery, so it remains to be seen how much time the switch-hitting outfielder may miss next season.

Since debuting Sept. 1, Dominguez — the Yankees’ No. 2 prospect, per MLB Pipeline — was hitting .258 with four homers and seven RBIs in eight games. He became the youngest player since at least 1901 to hit four homers in his first seven games.

Dominguez was slated to bat third Sunday against the visiting Milwaukee Brewers but was scratched with what the Yankees termed right elbow inflammation.

After starting the season at Double-A Somerset, Dominguez was promoted to Triple-A Scranton/Wilkes-Barre on Aug. 22. He played in 118 games between the two levels, hitting .265 with 15 homers and 76 RBIs. He went 13-for-31 (.419) in his nine games at Scranton/Wilkes-Barre.

–Field Level Media