A move to Old Trafford was mooted for much of the Premier League transfer window, with the Red Devils in the market for players of his ilk.
Fernandes, at 24 years of age, is considered to have plenty to potential to unlock alongside his current ability.
Former Blancos star Ronaldo, who is an international team-mate of Fernandes, believes a fellow countryman is ready for a step up in class.
"In the national team, you have a lot of talent, so I see the light at the end of the tunnel. Possibly this new generation will be the best at the talent level, but that's not enough.
"They have to want to. I have spoken to him [Fernandes]. I'm a captain who wants to help and be helped."
Fernandes formed part of Portugal’s UEFA Nations League-winning squad over the summer.
Ronaldo was also in that group, having previously helped his country to glory at the 2016 European Championship.
The countdown is now well and truly on to the defence of that crown next year.
Five-time Ballon d’Or winner claims confidence is high in the Portuguese camp, adding: "The atmosphere in the national team is spectacular. The last few years have been the most enjoyable.
"The most responsible for this is Fernando Santos and the president of the FPF."
Portugal have two Euro 2020 qualification contests to come in September.
The first of those will see them travel to Serbia, before staying out on the road to take in a meeting with Lithuania.
Ronaldo will be expected to lead the charge once more in those fixtures, but can expect to be ably assisted by the likes of Fernandes.