Watch: Javier Mascherano stumbles to ground with head injury, re-enters

The World Cup is going to remembered for a lot of glorious things, but one of the stains on the tournament continues to be the leniency with which head injuries

The World Cup is going to remembered for a lot of glorious things, but one of the stains on the tournament continues to be the leniency with which head injuries are treated. 

After Uruguay defender Alvaro Pereira was knocked out cold against England and then immediately re-entered after refusing advice of his team's doctor in the group stage, it caused plenty to call for a stronger concussion protocol and procedure in the international game.

Apparently, Argentina was either not paying attention or did not care to. In Wednesday's semifinal against the Netherlands, Javier Mascherano took a blow to the head in a collision with GeorginioWijnaldum about 25 minutes into the first half. The veteran put his hand to his head and proceeded to stagger to the ground like a punch-drunk boxer, eventually spending minutes on his back as trainers tended to him. Mascherano stepped off to the sideline as is typical for any player who spends time injured on the field and then immediately re-entered.

Perhaps Mascherano did not receive a concussion or major head trauma on the play and was medically fit to re-enter. It's not clear to say, though, considering the lack of examination prior to his re-entry. 

Watch the incident below: