It's not something that had previously common knowledge but Liverpool defender Virgil van Dijk could have died back in 2012, as revealed by one of his former coaches.
Van Dijk was just 20 at the time and playing for FC Groningen but his career, and more worryingly, life, was nearly over after a minor illness turned very serious.
He took ill after an Eredivisie game against Excelsior but officials thought it was just common sickness until later it emerged he had appendicitis, peritonitis and a kidney infection.
"Virgil was ill, but we didn't know the extent," Groningen reserve coach Dick Lukkien told FourFourTwo In an interview.
"The pain got worse and when his mum travelled to see him, she realised how bad the situation was.
"She took him to another hospital, which turned out to be crucial.
"I was shocked. When he returned to the club, he had changed from a big man into a shrivelled person. Luckily he managed to recover quite quickly."
With van Dijk's condition so severe, he was forced to have surgery that would save his life and was sidelined for the final two months of the season so he could make a recovery.
But it got to the point that the Dutchman even got as far as writing a will so that his mother would be taken care off financially if the worst did happen.
"I still remember lying in that bed," the centre-back was quoted as saying in 2012.
"The only thing I could see were tubes dangling out of me. My body was broken and I couldn't do anything.
"At such a moment, the worst scenarios were whizzing around your head.
"My life was at risk. My mum and I prayed to God and discussed possible scenarios. At some point I had to sign some papers. It was a kind of testament.
"If I died, a part of my money would go to my mum. Of course, nobody wanted to talk about it, but we had to do that. It could have been over."
Seriously scary stuff but fortunately van Dijk has come through it all and grown to become one of the best defenders in world football, captaining his country and being a crucial part of a Liverpool side that are having their best ever start to a Premier League season.