Mario Williams is not "most". CND I know that because of your medical background you've seen every negative aspect of the medical community. This is why people come to doctors and surgeons, they're at the worst point of the injury. This is why it's hard to expect something to be minor, because you are constantly subjected to the most extreme versions of said injuries, along with minor versions. Mario most likely strained an abductor or adductor, I don't really think he pulled his groin.
My question to you is, have you pulled your groin before? I have, on many different occasions, it's always been a day or two, 4 days at most injury. It's pretty darn common in the sports community.
No disrespect intended. Flamesuit on.