City scaled the heights last term as they became only the second English team to win the treble of Champions League, Premier League and FA Cup.
Now, as City prepare to begin the defence of their European crown at home to Red Star Belgrade on Tuesday, Walker has revealed manager Pep Guardiola wants them to prove themselves all over again.
The England right-back said at a press conference: “It’s our job to stay motivated. We’re at a massive club for a reason, because the manager believes in us and we’re all great players.
“It comes from within that you have to keep going. The hunger is still definitely in the changing room and from him as a manager as well. He still wants to win more.
“You can see what he is like in games and training. He doesn’t settle for second and we need to follow in his footsteps because he has managed some great teams that have won fantastic things.
“What we have done is in the past now. It is a new season, you draw a line under it.
“The manager did a diagram for the first game of the season. We start at the bottom of the mountain and we are climbing to the top.
“Our flag will always be at the top because we have won the Premier League and Champions League but we have to go again and again. It is what separates the good teams from the great teams.”
Walker has captained the team so far this season and looks likely to retain the armband following a squad vote to find a permanent successor to the departed Ilkay Gundogan.
Walker would not reveal who came top in the vote, which has taken place in recent days, other than to confirm he has been nominated as one of the group of five senior players who make up the captaincy group.
However, with the other main contender for the job, Kevin De Bruyne, currently out injured, it would be a surprise if the 33-year-old did not lead out the team for the Group G clash against Red Star.
Walker said: “The captains’ vote has come in and the five captains that have been chosen that will lead the team for the season and make sure all checks and fines are paid up.
“I’ve been very honoured (so far) and it’s a privilege to lead this special group of players out.
“I will continue to do that and hopefully lead by example on and off the field to ensure we are collecting the trophies at the end of the season.”