Heller underwent Tommy John surgery Friday.
The surgery is something of a surprise, as Heller's reported ailment was bone spurs, rather than a sprained UCL. Dr. Christopher Ahmad apparently performed Tommy John surgery and also removed a bone spur in one procedure. The typical Tommy John recovery timeline would see Heller able to return to game action sometime in the middle of the 2019 season. He was on the outside looking in this spring in the battle for the Yankees' final bullpen spot, so he's likely to end up at the Triple-A level once he's able to pitch again.