Ilkay Gundogan has labelled his Manchester City debut as "perfect" after the Germany midfielder made his first appearance for the club in their 4-0 thumping of Borussia Monchengladbach in the Champions League.

Following the torrential rainfall in Manchester on Tuesday, City had to wait an extra 24 hours to get their campaign under way, but the delay had little impact on Pep Guardiola's side as they cruised to victory courtesy of Sergio Aguero's hat-trick and a late effort from Kelechi Iheanacho.

And Gundogan, who was not named in Tuesday's starting line-up but was drafted in due to the absence of David Silva on Wednesday, was quick to express his delight after finally making his maiden appearance since arriving from Borussia Dortmund in the close-season.

"It's a perfect day for me," Gundogan, who won the penalty for City's second goal, told BT Sport. "To wait such a long time, it's brilliant to play and have a good first game.

"I tried to work hard and now I'm just looking forward to the next game. Of course it's not easy after such a long time out.

"Four months of rehabilitation is made more difficult especially when you don't have an opportunity to be tested, or even a friendly to practice.

"But I started from zero so to play for 80 minutes, and to play well I think, then I am very happy."

The victory takes City to second in Group C – level on points with Barcelona, who hammered Celtic 7-0 on Tuesday.

Brendan Rodgers' side are next up for City, but Pablo Zabaleta insists that Guardiola's men will take nothing for granted heading into the September 28 clash at Celtic Park.

"We played well. We probably could have scored a few more goals," the City defender said. "We created a lot of chances. I think we were on top from the first minute until the end.

"Now we have to play Celtic. People say they are the weakest in the group but I don't agree. They are a really powerful team, especially at home.

"We knew how important a win was – we are in a very tough group – so it's huge, and psychologically it was difficult to wait another 24 hours."