One of the clubs heavily linked with the Portuguese man's signature is his former side, who have already strengthened over the summer with the additions of Shinji Kagawa and Robin van Persie to the United squad.
The rumours come amidst a comment made by Ronaldo about how he is "sad" at Madrid.
Of course, this is Cristiano we are talking about. Being "sad" could range anywhere from having a bad piece of candy, to hating his time at the club and wanting a way out.
Chances are it's the first of those two possibilities.
Some believe the source of Ronnie's discontent may be as a result of the lack of support currently being shown by his Galacticos team-mates, who have apparently not spoken out favourably enough in regards to his conquest to be recognised as the best player in the world.
Ronaldo feels whilst Messi is backed up by his Barca colleagues, the players at Madrid are too concerned with themselves to show any real signs of support.
This is the typical egocentric arrogance one has come to expect from Ronaldo over the years—but it's kind of why a lot of football fans love him!
Rivals for the alleged "transfer" include Manchester City and PSG—realistically, the only two clubs who could afford Ronaldo.
One thing is for certain: this is the second time Ronaldo has spoken out about being unhappy at Real in just three seasons.
During his time with the Red Devils, Cristiano was generally content season in and season out.
Could we be about to witness one of the most breathtaking transfers in history this winter?
It's unlikely, but a man can dream I suppose.