Paris St Germain are in talks with Ronaldo's agent with a view to bringing the Brazilian to the Ligue 1 club.
Alain Roche, the man in charge of recruitment at PSG, has travelled to Brazil where he will spend around 10 days scouring the country's league for possible signings.
High up on his wishlist is free agent Ronaldo, who is close to making a recovery from a serious knee injury he had surgery on back in February.
PSG president Charles Villeneuve admits his club are following the double World Cup winner closely while the player's representative, Fabiano Farah, has revealed discussions between the two parties have already taken place.
''Yes, I have spoken to the representatives of PSG,'' Farah said in L'Equipe. ''They called me and we discussed certain things but I can't go into detail.
''Taking into account his list of achievements and his standing, he must have a club with an ambitious outlook who can offer him the possibility of winning major titles.''
Villeneuve added: ''Everything depends on the progression of his recovery from injury, if one day Ronaldo can rediscover his form of old or at least a satisfying level.
''We have some news on Ronaldo, we are following his progression. For the moment, I am leaving my people to deal with it all. But it is clear that I am open to anything.''
Ronaldo, 32, is currently in rehabilitation in Flamengo and is ''one or two months away'' from a return action, according to Paolo Figueiredo, one of the striker's physios.
He was linked in the summer with a move to Manchester City, who denied they would sign the three-time former FIFA World Player of the Year award winner.