Cesar Azpilicueta was taken to hospital after he suffered a sickening head injury during Chelsea’s defeat to Southampton.

The 33-year-old is believed to have been unconscious after Southampton substitute Sekou Mara attempted to volley the ball but only booted Azpilicueta in the face. It was a horrible collision and the thud could be heard around Stamford Bridge.

Azpilicueta needed oxygen as he was treated by medics from both teams for nearly 10 minutes on the pitch.

The defender was eventually taken off on a stretcher, wearing a neckbrace, but Chelsea manager Graham Potter revealed the 33-year-old was awake and speaking to loved ones while undergoing treatment.

‘He’s in hospital so he’s in the best place. He’s conscious and I think he was speaking to his wife – so that’s good,’ Potter confirmed afterward.

‘We were concerned – especially when it first happened but hopefully, he’s in the best place and we’ll keep monitoring him.’

When Azpilicueta was taken from the field, he was lucid enough to clap at supporters as they applauded him.

But teammates and opponents were left distressed by the injury, with Kai Havertz crouching down near Azpilicueta, hands over his face.

Potter was asked afterward if the defender had been unconscious.

‘I think he was. So we have to take all the precautions and make sure he’s ok but it was worrying, it was a horrible incident.’

Southampton interim boss Ruben Selles added: ‘I have not watched it back. Of course, I wish him a speedy recovery, I spoke to Willy Caballero to keep me posted on his state, and hopefully, he will be back to show what a good footballer and person he is.’

Azpilicueta’s nasty injury caused a lengthy second-half delay at Stamford Bridge and the officials added on 12 minutes at the end of the game. But Chelsea was unable to make it count as they fell to a second defeat of the week – following a Champions League loss to Borussia Dortmund – that piles more pressure on Potter.