Moving on to the management front, Mendieta is not convinced that highly-rated Bournemouth boss Andoni Iraola - who has previously worked at Rayo Vallecano - will be returning to his native Spain any time soon.
He said of potential interest being shown by Barca and Real Madrid: "I'm not sure. I don't think Andoni Iraola has the profile. I'm not saying he's not up to the job because of the size of it, I think he is, but I'm not sure the profile that those clubs will be looking at him at the moment.
"Certainly, Bilbao will look at him at some point, he will definitely be manager there at some point in his career, but maybe he will move to a big club in the Premier League. He is proving his value at Bournemouth and has shown he can bring success in England, so maybe that will be his path."
For now, debates regarding Mainoo, Kane and Iraola remain idle gossip, with there little substance to be found amid the speculation. That situation could change quickly, though, with all three boasting plenty of appeal to suitors around the world.