Question how do you up date your nba live roster for ps3?

May be...

Ok i haven't hooked up my ps3 online yet so once I hook it up to play online what do i do?Do i have to sign up to play online or what?Because im going online to update my rosters.

there should be an option under the my nba section..but anytime you play an online game it automatically updates

when you enter the online mode it will check and update your rosters