Because Miki is a better player and has more potential. But bad management makes it look like it is. I have no doubt this guy will be great elsewhere and Mane would be shit for us. We would make look Messi underwhelming, but that happens when you don't have a playstyle, tactics, setup and just throw individual quality on the pitch. That's why Pool signings have been that good. I can only laugh if some here really think guys like Mane or Wijnaldum are world beaters and more talented than our signings. But they get the best out of them, signing players who suit their system well, while we make nothing out of Pogba, Miki and Zlatan.
Really hope it changes and we give him a chance. I don't know what's exactly wrong with him and what happens in training, but if we get rid of him without even playing him then I can only blame our management. They should have known better, it's not like it was a secret that this guy could need time and patience to settle in a new league and team.