The 37-year-old has enjoyed a glorious career to date and is showing little sign of slowing down.
He helped guide Portugal to this year's World Cup in Qatar, starring in a 2-0 victory over North Macedonia.
This year he has become football's all-time top goalscorer and has continued to impress back at Man United, despite their overall poor form.
And it seems the prolific forward still has plenty left in the tank with former Crystal Palace and Southampton defender Fonte suggesting that he's far from done.
Speaking to White and Jordan, Fonte said: "I think he's left it pretty clear in his last interview, he's the one who decides his future.
"I think that physically he feels good, he feels great.
"If he had the chance to win it and the chance to keep performing at the highest stages then he'll keep playing, as he said.
"Nobody knows exactly what he has in his mind, so only he can decide his future.
"He wants to play and keep playing so I would assume that he will be in Qatar, and not only in Qatar but in the next Euros at least."
While Ronaldo will eventually hang up his boots, Fonte believes that the future is incredibly bright for the next generation of Portuguese football.
He said: "I must say, I haven't seen a squad like this next one coming up with so much talent and so much quality all over the pitch.
"I really believe that the future is bright. I fully believe that if we get it right then we are in major contention to be winning tournaments because we have so much quality and so much talent in Felix, Jota, Bruno Fernandes.
"We have centre-backs like Tiago Djalo, Ruben Dias and then you have Joao Cancelo, Diogo Dalot and Nuno Mendes.
"The love of football in this country is incredible. The focus on this sport is very, very high; obviously that's because of the past footballers that we've had and the influence that we've had so everybody looks to football as the main sport, even though we are very successful in other sports, football is the main sport in Portugal."