McNulty replaces Chris Miller, who was fired after last season. McNulty had been Arizona's wide receivers coach the past three seasons.
Reich spent the last six seasons on the staff of the Indianapolis Colts, the last one as wide receivers coach.
Reich spent 14 years in the NFL as a quarterback, nine of them with the Buffalo Bills. He was quarterbacks coach for the Colts in 2009-10 before switching to the wide receiver responsibilities last season.