Dennis Rodman says Antonio Brown is a case study on self-sabotage ... telling TMZ Sports the guy basically ran a clinic, "The school of how to ruin your career 101."
Rodman was leaving the Javits Center in L.A. on Sunday with his good friend Dr. Drew -- when the topic turned to AB's social meltdown over the weekend.
As we previously reported, the troubled WR let his Twitter fingers loose ... saying he's done playing in the NFL while taking shots at his former boss, New England Patriots owner Robert Kraft.