Seemingly in response to newspaper reports which suggested the 80-year-old former footballer had been in hospital for six days, he posted on social media to confirm he'd had surgery to remove a "suspicious lesion" last Saturday.
He wrote on Instagram: "My friends, thank you very much for the kind messages.
"I thank God for feeling very well and for allowing Dr. Fábio and Dr. Miguel to take care of my health.
"Last Saturday I underwent surgery to remove a suspicious lesion in the right colon.
"The tumour was identified during the tests I mentioned last week.
"Fortunately, I'm used to celebrating great victories alongside you.
"I will face this match with a smile on my face, a lot of optimism and joy for living surrounded by the love of my family and friends."
Just under a week ago the former Santos and New York Cosmos forward felt the need to deny reports he had fainted and had "routine exams".
He now says the tumour was discovered in the tests last week.
In February 2020, Pele's son, former Santos goalkeeper Edinho, said his father had become "embarrassed" to leave his house because he is no longer able to walk without assistance.
Pele, who is generally perceived to be one of the best footballers of all time, has had numerous health concerns in recent times.
In 2015 he had prostate surgery and in 2019 he was admitted to hospital again for a urinary infection.
Pele, who is reported to have scored 1,279 goals in 1,363 games is one of only four players to have scored in four different World Cups.