Rivers was named the Eastern Conference's top coach for the months of October and November for guiding the Celtics to a 13-4 record that tied them with Orlando for first place. Boston also is the only NBA team shooting better than 50 percent from the floor (50.4).
Popovich has his club off to its best start in franchise history. The Spurs got off to an NBA-leading 15-2 record, and are the only unbeaten team on the road (8-0).
Other nominees for the monthly honor were New Orleans' Monty Williams, New York's Mike D'Antoni, Oklahoma City's Scott Brooks, Orlando's Stan Van Gundy and Utah's Jerry Sloan.