Rumor, there is no certainty in it. After Ronaldo officially parted ways with Manchester United, no one has made an official bid on Ronaldo. The news circulating in print and electronic media is just a figment of the imagination, journalists continue to fry news about Ronaldo to attract reading interest from published news.
Ronaldo who still has big ambitions to appear in the Champions League, will choose a club that can make his dream come true. Chelsea is a good club and is still active in the Champions League, but with the current conditions it is very difficult for Chelsea to win the Champions League.
Don't be too surprised if there will be big news that comes suddenly because when talking about Ronaldo it seems like this always happens like when he comes to Manchester United and of course leaving Manchester United is also included so it's possible to transfer him later would also be a surprise I guess regardless of where he goes.