Aguero's rallying cry came after City's fourth consecutive defeat in all competitions, the first time Guardiola has gone this long without a victory in his career.

The Citizens have lost four straight games for the first time since August 2006, when Stuart Pearce was manager of the club and are 11 points behind Liverpool in the Premier League. 

Despite the club's recent run, the Argentine, who scored 260 times in 390 appearances for City, is confident that his former side can finish the season with more silverware.

"I think City are favourites to win everything, including the league, the [FA] Cup, the Club World Cup and the Champions League," Aguero said. "Whatever City has to play for, they'll be the firm favourites. I think it all depends on the mentality they have because it's not easy to always be the favourites."

Last season, City became the first team in history to win four consecutive Premier League titles but, with its form taking a dip and Guardiola out of contract at the end of the season, there is the potential for instability at the Etihad.

But, according to Aguero, the manager is the key to its past and future success.

That frame of mind is understandable, given that Guardiola is the most successful Manchester City manager of all time, having won 18 major trophies – 50 percent of the major honours in the club's history – with a win percentage of 72 percent.

"I think City are where they are because Guardiola knows very well how to keep that mentality," Aguero said. "For me, he's the key man for the club so that the players have the same winning mentality.

"Sometimes it gets difficult to win and it's normal, but Pep's team has been up there since he took charge, and that's something many people don't see.

"I think we have to acknowledge he's the reason his players have a winning mentality. He's strict and he makes the team be consistent every single game throughout the season.

"We should take our hats off because it's not easy to be there with the players every day, especially considering the players we're talking about.

"All the time, he's like, 'come on, we have to keep winning!' Living that every day can get exhausting sooner or later, but he's been doing this for days, months, even years, and I think that's why City are one of the favourites because Pep never rests and he never gives a rest to his players.

"That, for me, is the key to success for any team."