One of the last players I would sell. The chances of us winning the Champions League by playing possession football are extremely slim given that many other teams are better than us at it.
Our best hope is to exploit the wings with players like Cancelo, Sandro, and Costa to set up Ronaldo who is unmatched in his ability to score off crosses. If we sell Cancelo and potentially Costa this summer, then we've basically given up all our edge on the wings.
People say that relying on crosses is "wasting Ronaldo" but look at his knockout stage goals in his final years at Madrid and the majority are from crosses.