Mey, 23, was still pitching for the Dayton Dragons, the Reds' High-A affiliate, a year ago. On Thursday, he struck out the first batter he faced in Nolan Gorman. He proceeded to retire the next two batters to end the game, and peppered in some 100-plus mph heat along the way.

With the Reds demoting former closer Alexis Díaz on Thursday, the club promoted one of professional baseball's hardest-throwing pitchers. Right-handed reliever Luis Mey was recalled from Triple-A Louisville and is in the big leagues for the first time.

Cincinnati Reds prospect and reliever Luis Mey struck out the first batter he faced in his MLB debut, and pitched a clean ninth inning