Belgium doctor Kris van Cromburgge has revealed how he feared Dries Mertens may have been paralysed for life after his clash of heads with Wales' George Williams during Sunday's Euro 2016 qualifier.
Mertens was taken straight to hospital after some worrying scenes as he lay immobile on the pitch after clashing with Williams during the 0-0 draw.
It took over a minute for the Napoli forward to regain consciousness and he was kept in hospital for over 24 hours, during which his lower body felt numb.
Despite Mertens posting a picture of himself on Twitter giving a thumbs up from his hospital bed, Van Cromburgge said he was anything but serene.
I'm oke! Thanks for the support... pic.twitter.com/xgOhTAW2Jz
- Dries Mertens (@dries_mertens14) November 16, 2014
"It was dramatic," he told Italy's Radio CRC. "After the clash with his opponent, he lost consciousness for a minute and when he came around, he said he couldn't feel his legs. At that moment, I feared for his career."
Van Cromburgge did not express those fears to the player, despite his own concern.
"Dries was under shock and he immediately asked for reassurances about his career," he said. "The players on the field also had the feeling that something serious had happened because Mertens wasn't coming around and he was lifeless for a minute.
"We immobilised him immediately on the stretcher to prevent any movement from causing further damage to his body. He was paralysed and only after 24 hours did the situation return to normal."
Despite having recovered both from the shock and the severe concussion, Mertens will not be returning to Naples immediately.
Van Cromburgge added: "He will be there by the end of the week and then he will have to see a specialist before we can decide whether he is ready to play again or not."