Cristiano Ronaldo could play at the highest level until he is 40 years of age, according to former team-mate Ryan Giggs, who reached that milestone for Manchester United.
Ronaldo made a €112 million (£98.5m/$131m) transfer to Juventus last summer and has since celebrated his 34th birthday. However, the record-breaking Portuguese forward is showing few signs of slowing down.
Watch Champions League | Soccer Live Streaming | DAZN CA
He will be hoping to make it a sixth Champions League title this season – for a third different club – though Juventus have a lot of work to do in order to overturn a 2-0 deficit against Atletico Madrid in the second leg of their round of 16 clash.
“He is no longer the player that he was when he was at 19, 20 but he has adapted his game,” Giggs told Goal in Johannesburg, South Africa, during the UEFA Champions League Trophy Tour Presented by Heineken
“He went from a winger, who used to beat people, make goals, score goals to now really just an out-and-out goal scorer, and he scores every type of goal, headers, goals in the six-yard box free-kicks and every type of goal.
“He is also the best professional I have played with. The way he looked after himself, not only in training but also away from the pitch. The way that he eats, the way that he conducts himself.
"So, I’m not surprised that he is still playing and still at the top of his game.
“You still have to have that hunger, desire and dedication to go out and train and look after yourself - eat the right way, not drinking alcohol, getting enough sleep and enjoying it.
“Ronaldo, if you look at him, he still looks after himself. So, if he still has that hunger, that desire and enjoying it like I said, he can still go until 40 I think.”
Ronaldo was a team-mate of Giggs in the Manchester United team when they won the 2008 Champions League under Sir Alex Ferguson on penalties against Chelsea in Moscow.
They were both back in action the following season but Barcelona under Pep Guardiola proved too strong for United, just as they did a couple of seasons later when Giggs was on the losing side again.
"We would have been the first team to regain the Champions League which would have been special,” Giggs said. “That was probably the most disappointing game of my career. We didn't play well. We didn't turn up. I was really disappointed.
“In 2011, sometimes you just have to hold your hand up; we were up against a great team. It was very difficult for us... we still made it difficult for them, but it was of those times, probably the only time or a handful of times in my career, where we were up against a better team.
"I would have liked to have won more. Of course, we were in four finals - we got beaten twice by Barcelona; probably the greatest team I have played against... Messi, Xavi, Iniesta, Puyol, Pique - really top players in a top team. So, we would have liked to have won it a lot more, but it's a difficult trophy to win. I'm just happy I won it twice."
Giggs admits that it’s impossible to plan for the talents of Lionel Messi and that the only thing United could do in both finals was try to restrict the number of times the Argentine No. 10 received the ball.
“I don’t think you can plan to play against Messi,” he said. "What we tried to do was stop the ball from getting to Messi. So, if we could stop the ball from getting to Messi, then he couldn’t hurt us. But of course, it is very difficult.
“In that game, he had a free role where he could go wherever on the pitch, and you have Xavi, Iniesta on the pitch, you have to stop them as well, that’s the problem that we had. They had a great team, but to stop Messi is very difficult.
“Him [Messi] and Cristiano Ronaldo are probably on par, it just depends who you think is the best. Obviously, Ronaldo has won something internationally, his played in Portugal, England, Spain and now Italy. That is the difference between him and Messi.
“Then you look at Messi and he is doing things that no other player has done. He is scoring goals, making goals and they have both won so much in their career. So, there’s not much between them.”
Wales manager Giggs first tasted success in the 1999 final against Bayern Munich during a memorable season when United became one of only six teams to complete a treble.
“When you win it in 1999, I was 26 or 27 and you think 'okay this is the first of many finals at least', maybe winning it, but it wasn't until nine years later where we got to the final,” Giggs said.
"And it was different because it was against Chelsea; someone from your own league and, again, it was different because it went to penalties. It was a tough final in Moscow, against a very good team, but we managed to come out winners.”
The UEFA Champions League Trophy Tour Presented by Heineken gives fans around the world an opportunity to see the coveted UCL Trophy and meet legends of the competition in their hometown. South Africa is the first stop of seven places the UCL Trophy will visit in 2019 on the UEFA Champions League Trophy Tour Presented by Heineken. Next up, Heineken will be taking the UCL Trophy and legends, Carles Puyol and Alessandro Del Piero, to Indonesia.