'I feel better every day,' says Brazilian great Pele

"Friends, it's been a while since we talked about this. I want to let you know that I'm fine. I feel better every day," a masked Pele wrote on Twitter.

"I don't think even the mask for my protection can hide my happiness. Thank you very much to all of you who send me good energy daily."

His message, however, gave no indication of how his chemotherapy was progressing.

Pele, who turned 81 in October, said in September he would undergo chemotherapy for a tumour that was discovered while undergoing routine medical checks in Sao Paulo.

He later caused fans around the world to fear for his wellbeing after telling them: “I suggest you start to catch your breath to celebrate with me, because with each passing day I get closer to score a goal.”

The former Santos, New York Cosmos and Brazil player has suffered a series of health issues over the last decade, particularly with his hip.

Widely considered to be one of the greatest players of all time, Pele is the only male soccer player to have won three World Cup winner's medals, lifting the trophy with Brazil in 1958, 1962 and 1970.