From Slate.com:

On Saturday, University of Florida quarterback Tim Tebow got crushed in the chest by a Kentucky defender. As he flew backward, a teammate's knee knocked into the back of his head and his arms went limp as he flopped to the ground. Tebow vomited on the sidelines several times after being carted off the field, and he was eventually brought to a local hospital. The diagnosis: a concussion.

The reports are "cautiously optimistic" that he'll be able to play against LSU on October 10.  For someone who was apparently unconscious for two minutes, that seems like an unhealthily quick turnaround for an athlete.  Dr. Robert Cantu, who devised the grading scale for concussions, says Tebow probably suffered a severe level of damage and should take as much time to recover as possible.

I bring this up because of the occurrence of (possible) brain damage to MMA fighters.  If I'm not mistaken (correct me if I am), all UFC fighters who lose via (T)KO are required to receive brain scans.  Obviously, this policy is necessary because the rotational forces from a blow to the head are more likely to induce traumatic brain injury than the head-on collisions of American football.  However, MMA fighters are usually aren't forced back into combat ASAP.  Part of this is the nature of the sport - they fight on a contract-by-contract basis instead of having an entire season planned in advance, so it's easier to sit out for extended periods of time (especially when there isn't as many sponsorships on the line).  The reports in the article about pro football players trying to be tough ("If your vision gets blurry, just hit the guy in the middle,") and furthering the damage is painful to read, and I'm glad many MMA organizations are aware enough of these risks to take monitor of their brain-addled fighters.

I've been knocked out once (kick to the head during a soccer game), and while it was the worst migraine I've ever had, I still felt as though I had to play on through the pain.  The desire to continue for a top-level athlete must be overwhelming, yet to ask them to entertain us after such a critical injury is unfair.  Thankfully, he is apparently getting top-tier treatment.  Good luck, mate.