Former Manchester United fitness coach Mick Clegg claims Cristiano Ronaldo can play professional football till he's 41-years-old.
Ronaldo continues to bang in the goals for club and country at the age of 35, and he has showed no signs of slowing down despite picking up niggling injuries.
Clegg, who was part of Sir Alex Ferguson's coaching staff, reveals Ronaldo was the only player at United who could measure up to Ryan Giggs' work ethic off the field.
“Before Ronaldo, the best athlete in terms of work on his body was Ryan Giggs,” Clegg told Gazzetta dello Sport.
“He was the strongest, the most attentive to details. If Giggs played at United until he was 40, Ronaldo can play till he is 41.
“Cristiano was the only one able to go beyond the high standards of Giggs.”
Scroll through the gallery below to see the oldest players in football history: