One of Europe’s top goal keepers was injured in a Russian Premier League game after taking a knee to the face (video below at 0:50 mark). Andriy Dykan was attended to but continued to play, until things were bad enough he asked for a sub;
Spartak said Dykan had “broken multiple bones and suffered concussion” after being struck in the face by Zenit striker Alexander Kerzhakov’s knee.
The 34-year-old decided to play on following the collision early in the second half but 10 minutes later he asked to be substituted.
The Concussion Blog 
I just recently got a concussion in soccer as well. Prior to this concussion I had just gotten cleared from another concussion that took me 2 months to recover and then the first indoor soccer game I got to play, one of the guys rockets a ball from about 3 feet away and it hits me square in the temple. I blacked out for a minute and now I’m stuck recovering from another concussion. And the worst part is that spring training is coming up and I cant participate…