Speaking after the game, Guardiola, whose team play with Nike and adidas balls in the Premier League and Champions League respectively, lambasted the Mitre Delta, suggesting it was "not a serious ball for a professional game".

The EFL released a statement yesterday defending the ball and adding it would talk with Guardiola over his complaints.

The statement read: "The Mitre ball used in this season's Carabao Cup is of exactly the same technical specification as the balls used in the Sky Bet EFL and Checkatrade Trophy, all of which are tested in accordance with the 'FIFA Quality Programme for Footballs' and meet the 'FIFA Quality Pro' standard.

"All balls used in the professional game are required to meet this standard.

"Clearly, preference is a subjective matter, but overall the entertainment provided across last night's round-four ties would suggest that the ball used is not having a negative impact in the competition.

"We will look to engage with Mr Guardiola and Manchester City to fully understand any concerns in advance of their round-five tie."

Though City and Wolves are their respective division's top scorers - an honour Wolves share with Hull - neither could register a goal in normal or added time before the hosts won a shoot-out 4-1.

"The ball is not acceptable to play with... at that level," City boss Guardiola said after the match.

"We play with a different ball. It's not Nike, adidas I don't know, it's a different brand. It's unacceptable to play with the ball.

"That ball is not a serious ball for a professional game.

"I say that because we won, eh? If I don't win, I don't say that because after that it's excuses. As I won, I can tell you: it is not acceptable to play.

"If it's for the marketing, for the money, for many reasons, it's OK but it's not acceptable to play with that ball.

"No weight, nothing.

"(We get the balls for) one day or two days, but the ball is bad two days, one month, one year, two years. It's bad, it's bad.

"The ball is unacceptable for the high of level of the competition.

"All the players complain. I assure you all of them say, 'What is that?' Really. I am sorry Carabao Cup."

Guardiola's sentiment was echoed by City's Yaya Toure, who even claimed the Delta did not compare favourably with adidas' much-maligned Jabulani, which was used for the 2010 World Cup.

"I don't like it, to be honest," Ivory Coast midfielder Toure said.

"They can do better than that. It's too light. Even in my country they can't use those kind of balls.

"I think they have to be better than that because the ball was too soft. It's rubbish but that's fine.

"The World Cup one (Jabulani) was better than that one.

"A lot of players were complaining. The FA can try to do something because we just want to enjoy it.

"It's difficult to play with these kind of balls but we try to find a way. It's everything. Shooting - the ball is very light, when you touch it, it's floating, it's rubbish. And in this weather it's difficult."