Doc Rivers says he has no idea if he'll ever return to an NBA sideline ... the coaching great tells TMZ Sports his future in the sport is completely up in the air.
We spoke with Rivers -- who was recently let go from his gig with the Philadelphia 76ers -- outside Jon & Vinny's in LA this week ... and he made it clear his main focus is enjoying his recently-cleared schedule.
"I don't know what I'm gonna do," Rivers told us. "I'm just gonna enjoy life."
The championship-winning coach was fired back in May after going 154-82 through three seasons in the City of Brotherly Love .