How To Treat Knee Pain?

My son was in a wrestling match and another wrestler rolled over his knee. It hurts on the inside of his knee. He was able to walk without pain after meet, but after sleeping several hours, woke up with pain and it now hurts to walk on. It does not appear to be swollen and no bruising yet. His knee does not hurt when he lies still but hurts when he moves it and tries to walk. Using advil and ice, but does not seem to be helping?