Diaz is out of the lineup for Wednesday's game against the Guardians, Matt Kawahara of the Houston Chronicle reports.
Christian Vazquez will receive a turn behind the dish for the matinee game while Diaz rests after catching each of the Astros' last three contests. Diaz recorded a hit in each of those games, but he's still been a disappointment for fantasy managers through the first four weeks of the season with a .197 average, one home run, 10 RBI and five runs over 18 games.