Three draws and a midweek defeat by Aston Villa have seen last season's treble winners City fall six points behind leaders Arsenal, having topped the standings a month ago.

"I think for everyone in the club, it's good what we are living. I think it's necessary to live that. For a long time, it was about how good we are," Guardiola told reporters.

"Maybe we need it. It's terrible, we're unbeatable and we are now not able to win one game. In the big moments, I was realising that.

"Maybe for myself first, I need that challenge to prove I'm a good manager.

"For the players, it's a good challenge, that Aston Villa were miles away from all of us... And now we may not qualify for the Champions League next season."

City will have the opportunity to return to winning ways on Sunday when they visit Premier League newcomers Luton Town, who are 18th with just two wins.

Luton boss Rob Edwards had described City as the "best team in the world" but Guardiola is aware a trip to Kenilworth Road is no easy task after Liverpool were held to a draw while Arsenal needed an injury-time winner to seal three points.

"They're doing really, really well for the way they played.

"Top clubs and teams like Arsenal and Liverpool have struggled to win, it will be the same for us," he said.

"Hopefully, it doesn't make us weaker, thank you for the words (from Edwards). It's a football game and in that moment, we are not the best team in the world as we are not getting results.

"When you are winning games, you are the best team in the world. When you are not, it's a crisis. It can be exaggerated on one side but that's the reality."