Ronaldo ruptured tendons in his left knee against Livorno last month and is facing a lengthy spell on the sidelines.

Having suffered a number of knee problems throughout his career, the 31-year-old will struggle to regain top form, according to Pele.

"It's a pity but I don't think he will come back to the same level as before the injury," Pele said.

The three-time World Cup-winner became close friends with Ronaldo when he sustained a similar injury while playing for Internazionale in 2002.

"Back then I went to his home and we prayed," Pele said. "He recovered and had a great World Cup.

"Medical treatment has advanced since then but so has his age. I would like him to come back to 100% but unfortunately I don't think it will happen."