Warriors coach Steve Kerr played for four seasons in San Antonio under Popovich and helped the franchise to the 1999 and 2003 championships.
Morris hit a game-winning buzzer-beater from the wing to lift the Denver Nuggets over Golden State 117-116 at Chase Center.
Warriors were without Stephen Curry, Klay Thompson, Draymond Green and Andrew Wiggins on the second night of a back-to-back.
Milwaukee Bucks never trailed while racing to a 77-38 halftime advantage and handing the Warriors their fourth loss in five games..