For the people who don't have the patience to watch a five minute video (which is like 90% of this forum), the relevant part is at 3:35. Cliffs - Overeem's injury is a "through and through," meaning it wasn't just superficial damage to the skin and tissue. He had a muscle tear that had to be repaired. Probably not career threatening in and of itself, but there might be long-term issues related to muscle functionality where his lip was ripped up. Might permanently affect the way that his face looks and his speech.