Guinea pigs! what to dooooo!!!!!?

I got my guinea pigs a few weeks ago, now they are settling in fine. but my biggest worry is about the littlest one! he had a scab on his left ear, which is perfectly normal according to the vets! but, the scab has come off, but its left a big gouge out of his ear. it isn't open or bleeding, but if it gets infected ill be devastated. WHAT AM I GOING TO DO. PLZ HELP!