Horror as football star Nanu is hospitalized with ‘concussion & spinal cord injury’ after sickening clash with goalkeeper (VIDEO)

Ex-Real Madrid defender Pepe was left in tears after Porto teammate Nanu needed to be taken to hospital following a thunderous clash of heads with a goalkeeper during his team's game with Belenenses on Thursday evening.

An ambulance was called to the pitch moments after the 26-year-old Guinea-Bissau international collided with goalkeeper Stanislav Kritsyu while challenging for a high ball as Porto looked for a late winner in the deadlocked Primeira Liga game.

The right-back and Kritsyu were both left prone on the turf - but it soon became clear that Nanu's injury was a serious one.

Players from both sides gathered around the injured player with some - including the experienced Portugal international defender Pepe - looking visibly distressed throughout the ten-minute stoppage.

Nanu, who had been lying motionless on the ground, was quickly loaded into an ambulance after being fitted with a neck brace and was taken to the Sao Francisco Xavier Hospital for further medical evaluation.

"I wish our teammate Nanu a speedy recovery," said three-time Champions League winner Pepe after the game.

"The doctors in the ambulance told me that he was doing well, that he was already conscious."

A tweet issued by the club in the wake of the incident later confirmed the extent of Nanu's injuries.

"Nanu had a cerebral concussion and spinal cord injury with loss of knowledge," Porto announced. "At this moment he is stable, conscious and is already oriented in time and space.

"The examinations performed at Hospital S. Francisco Xavier did not reveal any alterations of clinical severity. He will continue to be observed at the hospital."

Nanu's injury comes at a time of increased scrutiny on the scourge of concussion within the sport, with links between football and the early onset of dementia being noted by medical professionals. 

Premier League star Raul Jimenez, of Wolves, suffered a fractured skull in another sickening clash on the pitch in November, while the likes of Petr Cech and Ryan Mason have also received serious head injuries during games which could have - but thankfully didn't - lead to life-changing injuries.