The Juventus forward will spearhead his country's defence of their continental title at Euro 2020 and Fonte is expecting him to have a big part to play at the tournament.
Fonte told talkSPORT: "He’s our leader, our captain. As usual he’s preparing in the best way. He’s one of the best professionals around. The numbers speak for themselves. He’s still going, he’s still a beast, so expect nothing else but greatness."
Portugal face a tough group that includes Germany and France and could then come up against England in the last 16 - a meeting former Premier League defender Fonte would relish.
He said: "It would be great. On a personal level, I’d love to play against England. I have fond memories from my time playing in the Premier League so what a great challenge it would be as England has a great squad as well."
Ronaldo led his country to glory back in 2016 and described the tournament win as the "most important" title of his career, despite being injured in the final.
He said: "The start of the UEFA European Football Championship 2016 was going well for me but then I was sad because I got injured [in the final vs France],"
"By the end of the match I was crying with happiness! I experienced three types of feelings and emotions in that game, but at the end of the day it was unbelievable what I felt!
"It is probably the most important trophy that I’ve won in my life."