30-year-old Pryor -- a former star athlete at Jeannette H.S. -- hooked up his alma mater's boys' basketball squad with Paul George 4's ... just in time for the district playoffs.

TMZ Sports talked to head coach Adrian Batts -- who coached the NFL stud back in the day -- and he tells us Pryor promised the kids he'd get all 12 players on the squad new kicks if they made the playoffs.

Jeannette went 15-7 (they won 14 of their last 15 games) and made the playoffs ... so true to his word, Pryor went shopping for PG4's.

Coach Batts says the kids were super-happy and appreciative of Pryor.

And get this, it's not the first time TP got gifts for the team ... he set the kids up with new LeBron's last month.