Ruben Dias defiant against Manchester City's critics after poor run of form
City slumped to a fourth consecutive loss in all competitions with a 2-1 defeat at Brighton & Hove Albion in the Premier League on Saturday, marking the first time Pep Guardiola lost four games in a row in his managerial career.
City, who are chasing an unprecedented fifth straight Premier League title, were also dumped out of the League Cup by Tottenham Hotspur.
"I would say, please doubt us, doubt us, feel welcome to do so," Dias told British media on Monday.
"When we did the treble, we even called it the dark January. We had a tough period. But it is what it is.
"What matters is how you bounce back from these moments. That's why our team has won so much because in moments of difficulty, the characters come up and we stay together.
"We don't find people to kill, we find people to bring into the cause and fight together. That's what we need to do once again. Until it's done, it's not done."
City's campaign has been hindered by a rash of injuries with Ballon d'Or winner Rodri, John Stones, Jack Grealish and Oscar Bobb among those facing spells on the sidelines.
They host Spurs in the league on November 23 in their first game back after the international break.