New details from the Joey Porter arrest ... cops say the Pittsburgh Steelers assistant coach roughed up a bouncer at a South Side bar after the game last night ... in a VERY boozy altercation.
According to the court complaint ... an off-duty cop arrived to the bar around 9:30 PM to find the former linebacker "standing over" the doorman.
The doorman told Porter, "Last time you were here, you threatened to kill me. You need to leave. You are not getting in."
At that point, cops say "Porter lunged at [the bouncer] and grasped [him] by his arms" .