My husband was mugged when he was 12, and wound up with a concussion. He doesn't remember the incident. He was kept in the hospital for 2 days. When he was discharged, the doc told his mother he should take it easy... so my super-over-protective MIL forbade him from participating in ANY extracurricular activities for the rest of the school year. Y'know, because it's so easy to get a concussion from singing in the choir.
Anyway, he was back at school about a week after the attack.
Hope your son and the other wrestler have speedy recoveries.
