Speaking to BetVictor, Mills said: "Mikel Arteta is the best man to replace Pep Guardiola at Manchester City, without a shadow of a doubt. He's worked with Pep, he knows the way City play and he can come in with the same level of intensity as him. I think it will be a concern. It's like trying to replace Jurgen Klopp, Arsene Wenger or Sir Alex Ferguson. .
"The hierarchy at City have to be looking for a successor now and I'm sure they are. There are lots of coaches winning in the City Group for instance. It's a concern for City but when you look at what they've done in the past, the senior figures they've brought in to manage the academy and recruitment, you have to put faith in them and hope that there is a good succession plan."