Mengden (0-1) allowed two runs on six hits, struck out five and walked four over 5.2 innings in a 2-1 loss to the Reds on Saturday.
Making his MLB debut, Mengden worked around three of his four walks, but the one he didn't cost him the game. Mengden walked Joey Votto to lead off the third, and two batters later, Jay Bruce hit a two-run homer. Otherwise, the rookie had an all-around solid MLB debut, throwing 69 of his 104 pitches for strikes and inducing 12 swing-and-misses.