My Son Has What Looks Like An Infected Hair Follicle

My son has what looks like an infected hair follicle on his knee. It looks like a pus blister with a hair in the middle. It hurts to touch, but we have not drained it. He has been putting bacitracin on it. He is a wrestler, and didn't want to pop it for fear of having an open lesion before a competition. Should it be drained, or will it dry up by itself? He will have his knee bandaged when he competes.... that's if the officials don't deem the clogged follicle a problem