Liverpool youngster Ben Doak caused some concern at the latest UEFA Youth League game.
Doak was seen collapsing on the pitch during a match against Sporting this week.
Medics had to race onto the field, as he was not able to stay upright after clashing with a Sporting player while going for a header.
He was eventually subbed, but did manage to groggily get back onto his feet.
Fans will be hoping that Doak did not suffer any significant or long-term issue as a result of the knock.
Concussions have become a significant talking point in the sport over the past few years.