Midfielder Fernandinho, who had been preparing for such an eventuality since the summer, filled in as a makeshift defender and looked comfortable in Wednesday's 3-0 Champions League win at Shakhtar Donetsk.

Yet with City now frequently in action midweek as well as at weekends, there are doubts the 34-year-old will be able to start every game.

Coming after last weekend's surprise error-ridden defeat at Norwich, City have received some rare criticism in recent days – but Silva is taking no notice.

"People can criticise and say what they want," the Portuguese said. "We don't need to prove anything to anyone after what we've done the last two seasons. We're relaxed.

"Of course we're not happy because we want to do better and we know losing against Norwich isn't ideal, but all teams have good and bad moments. It's impossible to stay three seasons, only with good moments.

"Sometimes you will have bad moments and it's the way you react to those bad moments that show how good a team you are and that's what we'll try to do. Every time we've had bad moments in the past we've always reacted well, and that's what we'll try to do again."

Shakhtar did not provide a stern test of City's unfamiliar Fernandinho-Otamendi centre-half pairing in their Group C encounter in Kharkiv. Goals from Riyad Mahrez, Ilkay Gundogan and Gabriel Jesus ensured City won comfortably as they visited the Metalist Stadium for a third year in succession.

City looked good in attack with Kevin De Bruyne also prominent but their efficiency at that end of the pitch is not in question. It is at the back where they quickly need to find a winning formula and Silva felt Fernandinho looked the part.

He said: "We saw last season that he's able to play in that position. He's very intelligent and when you understand the game and you're intelligent like he is, it's easy."

Gundogan was also impressed by the performance of the Brazilian and expects him to play a critical role in the weeks ahead.

The German said: "He's going to be massively important there. He's vital now.

"We have two defenders out at the moment and so in the next games we will need Dinho even more.

"It's going to be vital to stay stable at the back, then up front we're always able to score."