Pele feels "depressed" and is reluctant to leave the house due to problems with his hip, according to his son Edinho.
Brazil great Pele, who will turn 80 in October, has long since suffered with hip issues and requires a walking frame to get around.
Many of the three-time World Cup winner's recent public appearances have been in a wheelchair.
"He's very fragile in relation to mobility. He had a hip replacement and didn't have ideal or adequate rehabilitation," Edinho told GloboEsporte.com.
"He has this mobility problem and that has set off a kind of depression. Imagine, he's the King, he was always such an imposing figure and today he can't walk properly."
Edinho added: "He's embarrassed, he doesn't want to go out, be seen, or do practically anything that involves leaving the house. He is very shy, reclusive."
Pele spent 18 years at Santos, making 1,281 appearances and scoring 1,091 goals – though not all of those came in official matches.
He remains Brazil's leading goalscorer with 77 and is considered one of the greatest footballers of all time.