Ryan Giggs believes his former Manchester United team-mate Cristiano Ronaldo can play on until he's 40.
Ronaldo recently scored his 101st international goal for Portugal at the age of 35 and has shown no signs of slowing down in recent years.
Giggs, who himself played for the Red Devils until he was 40, is adamant Ronaldo can continue playing until a similar age.
"He'll have to be at the right club obviously. I was at a top club and played until I was 40, and I can see him going on and playing until he's 40 as well," Giggs told the PA news agency.
"He looks after himself - he eats right, rests right and lives for the game - and is the best professional I ever played with.
"I saw him at the start of his career and you could never foresee him going on to score this amount of goals.
"He was a talent and a brilliant player who excited you. Cristiano was always a student of the game, and just like me he always looking for that extra edge.
"He was always in the gym and had it in his mind how good he could be. He scored 40 goals in one season at United and since then what he's done is remarkable."
Giggs announced his playing retirement in 2014 at the age of 40 after 24 years playing for Manchester United's senior side.
Ronaldo is currently contracted to Juventus until 2022 and has previously hinted that he could play on into his 40's should his body allow him to remain at his best.
"Several years ago, the age of playing football was until 30-32, but now, you find those who are 40 years old playing on the field," Ronaldo said in late 2019.
"The moment my body is no longer responding in the right way on the field, then it would be the time to leave.
"My success in my field is the result of hard work, and a way of living. I work continuously to improve my mental and physical abilities.
“I know my body 100 per cent, and I always maintain a diet that brings me the physique that makes me different. Everyone knows my way of living, and my life is devoted to football."