The midfielder says he has undergone chemotherapy, after having surgery following the discovery of a tumour, which was first noticed last year.
Jonas Gutierrez: "When I was told I had cancer, I went home in tears.
"In May 2013, I felt very tough pains on my testicle. After some wrong diagnosis, an ultrasound detected the tumour.
"I came here and I assumed the costs despite having a contract with Newcastle. Money is not important. What is important is my health. I had to start chemotherapy.
"This is the most difficult match I've ever played. You start thinking about important things when you have problems like this one.
"Some guys like (Gabriel) Heinze gave me strength.
"After surgery, I told (Ezequiel) Lavezzi, (Martin) Demichelis and Coloccini, who is very close to me. We've played together at Newcastle for six years and he calls me. He is almost a member of my family.
"I decided to reveal all this because I think this is a difficult moment, but there is nothing wrong with this. These things may help other people."