The Sun says an Old Trafford return would cost at least £65million.
Nike representatives flew in to London to also talk about the renewal of their shirt sponsorship agreement with the Red Devils.
But top of the agenda was talks about how they could help the club get Ronaldo.
Nike is desperate to get the Portuguese star back to the biggest football club that wear their logo.
They currently sponsor Ronaldo in terms of boots and sportswear but are frustrated that he runs out in an adidas shirt with Real Madrid every week.
They believe their global brand would be even stronger with him back in a Nike United shirt.
Can Nike's influence tip the balance? Or will Real convince Ronaldo to stay? Give us your shout below...