Derek Fisher is going to bat for his boy, Luke Walton -- telling TMZ Sports he's not the loser LaVar Ball says he is.
Lonzo's dad went on a tear against the Lakers coach on Tuesday saying Luke is to blame for Lonzo's uncertain future with the Lakers.
Remember, LaVar had previously said Lonzo was going to make an immediate impact in the NBA -- and he and LeBron would lead the Lakers to championship, ASAP.
But now that Lonzo's on the trading block, LaVar is pissed and he's been bashing Luke Walton on the radio.