"I'm making it official, I'm no longer a Knicks fan!!!"
That's Michael Rappaport officially ENDING his NY Knicks fandom -- saying he's "disgusted" with the team for firing head coach David Fizdale and can no longer justify rooting for 'em.
"I'm serious. I am a fan of the past Knicks. I'm not rooting for this team."
Rap says the only way to send a message to Knicks management is through a celebrity boycott -- and he's calling out the stars by name!
"Jerry Seinfeld Howard Stern, Chris Rock, Tracey Morgan, all the cast of SNL .