Fulham midfielder Kevin McDonald revealed he has battled a chronic kidney disease throughout his career and will have a transplant next month.
Having been diagnosed at the age of 18, McDonald has been under doctors orders throughout a playing career which has included 500 professional appearances for the likes of Dundee, Sheffield United and Wolves, and five international caps for Scotland.
The 32-year-old, who has not featured for Fulham this season, says he hopes to play again after his scheduled transplant in April, after friends and family put themselves forward to become donors.
"I've been fighting a chronic kidney disease, or kidney failure ever since I started playing football. I've had it my whole career and obviously been under the orders of the doctors throughout my whole career," McDonald told FFCtv.
"No one sees this part of football. People just see you on the pitch and they have their opinions of you on the pitch and that's that. I just wanted to come out with this.
"I've had a lot of people asking about 'Why am I not playing, why am I not going out on loan' and this and that and it is something that we didn't want to share until this moment because obviously what's coming up it needs to be said now.
"So it's just to make everyone aware that I've had a chronic kidney disease my whole playing career and that's where it's at."
McDonald was left out of Scott Parker's two 25-man Premier League squads this season and he was expected to leave Fulham on loan in January, but he has revealed why that did not happen.
"I've known I've needed a kidney transplant for nearly 12 years now. I've loved my whole career in football but at the same time, in the back of my mind, my health has always been my priority. Football is a game but we're talking about life threatening diseases," he said.
"I've got one kidney that doesn't work at all and one kidney that's about 10 per cent now. I've been playing with stage 1, to now stage 5 kidney disease, which is chronic kidney disease, kidney failure."
He added: "It's a part of me opening up about it, people build these things up and of course there were certain reasons why to not tell anyone, so people and football clubs and businesses might not want to employ you as such, so there was reasons to keep it (quiet).
"But now, knowing that I'm towards the end of my career I've taken the decision to pick health over football, this season especially – and we just want to get it over and done with to be honest with you. It's been creeping up on you for so long and it's kind of like I'd rather go get it done and get on with the recovery again."
While McDonald has not been on the pitch for Fulham this season, he has been building up his coaching experience with the under-23s, but said he has a desire to continue to play following his surgery in the lower leagues.