Walker has spent six glorious seasons with City, winning almost every trophy imaginable. But he wants his side to be talked about as among the best teams the Premier League has ever seen. And he knows that, without the Champions League, there will always be a question mark hanging over Pep Guardiola's side.
Despite lifting a fifth Premier League crown in six seasons, reaching a record 100 points in 2018 and collecting six domestic trophies, including beating Manchester United in Saturday's FA Cup final, Walker believes that in the eyes of many people, City are still not regarded as the very best.
He believes that title, for now, belongs to United's treble winners in 1999 and the Arsenal 'Invincibles', who clinched the 2003/04 title without losing a single game. But he knows that if his side can beat Inter in the Champions League final and complete a treble of their own, the debate will be over.
"I think that United team, along with the Invincibles, is probably up there with the best Premier League teams of all time," Walker tells a pack of reporters at City's training ground four days before the final in Istanbul.
"What us and Liverpool, to a certain extent, have done where we have been battling for the last number of years, I think we should be in consideration. Both teams as we both have fantastic players.
"But they have silverware and they have got the big Champions League trophy that we can never say we have got. For us to be in contention of talking around that we need to go and pick up this one."