Under manager Pep Guardiola, City have become a ruthless winning machine – but getting motivated for new campaigns hasn’t got any more difficult.
Walker added: “For us to go and do four in a row off the back of a Treble was a great achievement. To pick yourself up and go again after such a high, plus we won the Super Cup and Club World Cup as well, was especially important.
“Now, why can’t we go and do five in a row? Why can’t we go and do something I don’t think will probably be ever be done again? That’s the motivation we have to create from us as a group of players, from me as a captain.”