My Son Was Kneed In The Jaw Playing Basketball. Then

My son was kneed in the jaw playing basketball. Then hit a second time by his brothers elbow. there is a very firm "knot" in his cheek, with redness isolated to knot. With it only being soft tissue and no laceration, are there any potential risks? We were just planning to let it ride its course, but with the second recurrence I am more concerned. No tenderness to the jaw bone.