A Brooklyn man who was nearly killed in a drive-by shooting over the weekend says the gunman was trying to silence him — because he’s a witness in a sensational 2009 Manhattan slay case.

Juan Guerilus, 30, blamed the 4:30 a.m. shooting outside a club in Flatlands on Sunday on his pending testimony against a man accused of killing popular deejay Omar “Pablo Picasso” Trent, law-enforcement sources told The Post yesterday.

Guerilus, shot five times, was in critical but stable condition at Brookdale Hospital yesterday, with a cop outside his room.

Sources confirmed that Guerilus is one of at least several witnesses in the Trent case and that officials are investigating his claim.