In High A Salem, 20-year-old Red Sox pitching prospect Michael Kopech dominated in his Carolina League debut Thursday after missing three weeks with a muscle strain in his upper calf/lower knee region.

Though Kopech walked three batters, he allowed just one hit in four innings while striking out six — including a nine-pitch striking-out-of-the-side in the fourth inning in which his final pitch was (according to the scoreboard) a 101-miles-per-hour comet for a called strike three.

One radar gun had the hard-throwing righty sitting at 97-100 m.p.h. throughout his outing, topping out at an Aroldis Chapman-esque 103. Just two big leaguers this year — Chapman (39 times) and Mauricio Cabrera (nine times) have thrown a pitch that registered at 102.0 m.p.h. or above. Kopech has also showed an 89-92-m.p.h. slider and a decent — if largely unnecessary — changeup.