Jan Vertoghen has revealed how he played on for Tottenham despite struggling with dizziness for almost a year after his collision with Toby Alderweireld in the Champions League semifinal last year.
The Belgian now plays for Benfica after Tottenham refused to offer him a new deal at the end of last season.
He was speaking recently after a new plan for concussion substitutes is being considered from the start of next year.
Vertonghen struggled in the final months of his Tottenham deal due to the effect of the clash of heads that he suffered in that game.
He said that he had to play on because he was in the final year of his Tottenham deal and he wanted to earn another contract at the club.
As the games kept coming thick and fast, the effect was worsening every time he had a collision in a game or training.
He said that it was the last lockdown from March which gave him the chance to rest, recuperate and feel better.
Vertonghen told Belgian outlet Sporza: “Everybody thought I was angry at Mourinho but at that moment I just couldn’t go on anymore.
“I had only one year of contract left, so I had to play. But when I played, I played badly.
“I was in a period where I could not [perform how] I should have. I even thought he played me a lot compared to how I performed.
“Lots of people don’t know it but I suffered a lot from that hit: dizziness and headaches.
“I should not have continued playing, it affected me in total for nine months and that’s why I couldn’t bring on the field what I wanted to.
“I just didn’t know what to do. It was game after game and training after training. Every time there was a new impact.
“Then the lockdown came and I was able to rest for two months, after that it was a lot better.”