Dennis Rodman has a big supporter ... John Salley -- who says he LIKES the idea of The Worm as an NBA coach and thinks Phil Jackson should give him a shot.
Rodman threw his hat in the ring for Knicks job earlier this week after Derek Fisher got the ax -- and even called in to the "TMZ Sports" show on FS1 to make his pitch to the team.
Salley says his former Detroit Pistons is a defensive genius -- and could definitely help a team ... and should be taken seriously!