Current rumours point to Atletico. Which would make sense as they need an obvious replacement for Griezmann (not to say he is currently as good as him, but he'd be a natural for his position is what I mean). That said, I could see City (more than United) spending the big bucks as well.
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Also, apparently, Valencia has rejected a 70M€ offer for Guedes. lol. They might regret that soon enough haha