Chris Brown's Manager: I Didn't Steal Your Money and Oops ...You Forgot to Fire Me!

Chris Brown's manager made good on his threat to add defamation to his lawsuit against Brown, and says there's no way he could have stolen the singer's cheddar.

Hours after Brown posted 2 videos saying Mike G had been fired for stealing his money, the now estranged manager filed new legal docs. In the new lawsuit, he says he's never had access to Chris' money because another business manager is solely responsible for finances.

Even though in the videos, Chris says he'd canned Mike over the cash ... we're told Mike claims he never got a termination notice until AFTER he filed his lawsuit.

We broke the story ... Mike G's also suing for assault, battery, false imprisonment and breach of contract after what he says was a bloody beatdown by Chris.

Mike's Lawyer, Patty Glaser, released this statement -- "Sadly, Chris Brown is once again lashing out against those who were closest to him and is refusing to accept responsibility for his actions. Making up false claims against Mike G to deflect attention away from his continued violent behavior is shameful. We are looking forward to our day in court when Chris Brown will be held accountable.”