Banning Donald Sterling was "very difficult" ... but it's business

 

NBA Commissioner Adam Silver Says ... making the decision to ban Donald Sterling from the league for life was "very difficult" ... but it's business -- and it had to be done.

Silver was out in NYC yesterday when he began talking. TMZ Sports asked if his personal relationship with the disgraced Clippers owner -- which spanned more than 2 decades -- made it even harder to dish out the punishment. Silver's answer seems pretty genuine.

But at the end of the day, Silver says ... "It's business. And I think he understood that as well."