Andre Drummond says he's a HUGE fan of his new head coach, Dwane Casey -- and tells TMZ Sports he can't wait for Casey to join the Pistons so they can kill it next season.
"Love Dwane Casey," Drummond told us at the Fortnite Pro-Am at E3 in Los Angeles ... "I'm really excited to have him."
Casey was the head coach of the Toronto Raptors -- which put up the best record in the East before being swept by the Cavs in the playoffs for the 2nd straight year.
Casey was fired -- despite winning the National Basketball Coaches Association Coach of the Year.
But, the way Drummond looks at it ... Toronto's loss is definitely Detroit's gain!