Keith Olbermann -- Clippers Should REFUSE TO PLAY ... Until NBA Punishes Sterling

The L.A.. Clippers should BOYCOTT the playoffs ... and refuse to step on the court until the NBA takes action against Donald Sterling ... so says Keith Olbermann.

Olbermann went to Twitter this morning -- after TMZ Sports posted audio of the Clippers owner telling his GF not to bring black people to his games -- and railed against Sterling.

"time for #Clippers players to step up. Refuse to play till NBA moves against this racist jackass #Sterling. NBA can't defend him.'

Olbermann also notes, "I was banned by the #Clippers for criticism of the front office - in 1986. This made me the envy of every other LA sports media person."