Lonzo Ball needs to back up his dad's trash talk or it's gonna be a looong season ... so says Kenny Smith.
The "Inside the NBA" star says LaVar Ball's antics have "put a bullseye" right on Lonzo's back -- and Patrick Beverley ain't gonna be the only one who's gonna take a shot.
The good news for Lonzo ... Kenny says it's "just one game" and he'll shut up the haters if he bounces back strong.
He even broke out a Rocky Balboa-ish quote for inspiration ...