'SNL' Star Chris Redd Undergoing Surgery After Attack

Chris Redd is about to enter the final stage of recovery after his brutal attack in NYC ... and this one will require him to go under the knife.

Sources close to the 'SNL' star tell TMZ ... Chris is scheduled to undergo surgery Tuesday in the Big Apple to finish the job of permanently repairing his busted nose. Now that it's been a couple weeks since the initial injury -- and the swelling's gone down -- our sources say a doctor will have a clear view to figure out how to fix it.

We're told the procedure will consist of breaking Chris's nose back into the correct place ... and then letting it all heal in hopes the structure returns to its original form. There's a lot of damage ... remember, one of the bones in Chris' face was cracked into 3 pieces.

Our sources say he'll be under general anesthesia for about 2-3 hours, and a plastic surgeon who specializes in this sort of thing will be overseeing the operation. While it might sound cosmetic, we're told Chris isn't aiming to change anything about his appearance.

Remember, this all started after a guy punched Chris in the face with brass knuckles in a failed attempt to steal his chain. It left the comic in bad shape, with stitches in place as a temporary fix. No arrests have been made and cops are still looking for the assailant.