They kept him for a while because he had a mild concussion.

It could be a mild concussion, or something much more serious.

I can only hope he has nothing more dangerous than a mild concussion.

A mild concussion could have disabled him for a couple of days.

Mild concussion still seemed to have him in its grip.

He suffered a mild concussion, but returned to the team later in the game.

But we've given him a thorough going over and I'm sure it's nothing more serious than a mild concussion.

It is sometimes hard to tell the difference between a mild concussion and a more serious head injury.

He was diagnosed with a mild concussion and sent home.

Last year against Philadelphia, he also suffered a mild concussion.