Pele has been hospitalised to undergo treatment for a colon tumour, as reported by Reuters.
The 81-year-old returned to the Hospital Albert Einstein in Sao Paolo, where he underwent surgery to remove a colon tumour in September, on Wednesday.
The tumour was spotted just over four months ago when Pele visited the hospital for a routine check-up, delayed by the Covid-19 pandemic.
Following the operation, it was confirmed that he would need to undergo chemotherapy as part of his recovery.
The Brazilian icon spent a month in hospital before he was discharged in October and has remained positive throughout his treatment.
He received thousands of messages of support and thanked fans after leaving intensive care.
"My friends, this is a message for each of you," he wrote on Instagram.
"Don't think for a minute that I haven't read the thousands of loving messages I've received around here.
"Thank you very much to each one of you, who dedicated a minute of your day to send me positive energy. Love, love and love!"
Pele's daughter Kely Nascimento also paid tribute to those fans who shared messages of support for the legend on social media.
"I would like to thank you very, very much, from the bottom of my heart, for all the loving and concerned texts, DMs, zaps and emails I have received," she wrote.
"I haven't had time to answer them all yet, but I read it and feel embraced!"
Pele is widely regarded as one of the greatest footballers of all time as the only man to win three World Cups.
"For Brazilians, speaking about Pele is speaking about an entity, speaking about something far superior to everyone," once said two-time World Cup winner Ronaldo.
Pele also won six Brazilian titles and the Copa Libertadores twice with Santos before starring in America with New York Cosmos.
"Pele revolutionised football," once said Brazilian World Cup-winning captain Cafu. "Pele stopped a war. Pele united countries, united families.
"There was no race problem, language problem. I was born in 1970. In 2002, I became a world champion. I was captain.
"I had the honour of receiving the World Cup Trophy from no less than whom? Pele! Man! If I say any more I'll cry. It's really emotional!"
Pele became an ambassador for the game after his retirement in 1977, winning the BBC Sports Personality of the Year Lifetime Achievement Award in 2005.
"I think Pele was better than all of them," once said his Brazil team-mate Tostao. "For me there's no comparison. He didn't have one defect.
"[Diego] Maradona was spectacular, but he wasn't on Pele's level physically, he didn't score the numbers of goals Pele did.
"[Lionel] Messi's spectacular, but he doesn't head the ball like Pele did, he doesn't shoot as well with both feet, he doesn't pull off the moves that Pele did.
"Cristiano Ronaldo is an exceptional player, but he doesn't have the ability that Pele had and he doesn't pull off the incredible passes that Pele did.
"If you take the qualities of Cristiano Ronaldo and Messi, put them together, then you'd have a player to compare to Pele!"