The English Football League (EFL) has responded to Manchester City manager Pep Guardiola's complaints about the ball used in the Carabao Cup, saying that it meets the required standard.
Guardiola said after Tuesday's Carabao Cup fourth-round tie against Wolves, which City won 4-1 on penalties following a 0-0 draw, that the Mitre Delta EFL ball used in the competition was "unacceptable" due to its lightness.
The EFL released a statement on Wednesday saying that it is happy to speak with the City boss about his concerns, but that ultimately the ball meets all FIFA criteria.
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 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."
Mitre also issued a statement addressing the controversy, highlighting how teams receive balls in advance of matches.
"As a British football brand, we're extremely proud of our long-standing history and partnership with EFL and the beautiful game at all levels," a spokesperson said.
"We're passionate about the game and obsessed about everything related to ball technology. We work with professional players and clubs to develop and test our pro balls and independent testing by EMPA [Swiss Federal Laboratories for Materials Science and Technology].
"We totally appreciate that all balls feel different and that's why we made sure competing teams were sent balls well ahead of the tournament for training."
City midfielder Yaya Toure has backed Guardiola's complaints about the ball, saying it is worse than Adidas' controversial "Jabulani" ball, which was criticised by players at the 2010 World Cup.
"I don't like it, to be honest, they can do better than that," Toure told reporters. "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 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."
Meanwhile, Toure also hailed City keeper Claudio Bravo after he saved two penalties in the shootout against Wolves.
Bravo had already come to City's rescue during the 120 minutes with a number of fine saves in one-on-one situations and Toure was delighted for his teammate after a difficult first season following his move from Barcelona, in which he was heavily criticised.
"He was the best player -- [it's] very enjoyable for him," Toure said. "It's very important for him. We play so high and sometimes you need that kind of experience. Claudio has experience and the criticism he received last year... He's shown that he deserves to play in this team."
Bravo has also been a penalty shootout hero for Chile in recent years with dramatic wins in the 2016 Copa America final against Argentina and in the 2017 Confederations Cup semifinal win over Portugal.
"Yes for Chile, for everything and in the training ground," Toure said of Bravo's penalty-saving ability. "We try to work on that. Sometimes the manager will use us and we'll have some sort of competition between us. He's very good Claudio."
Asked if Bravo had ever saved a penalty from Toure, who has never missed for City, the midfielder joked: "I don't remember him, no. He doesn't touch mine."
ESPN FC's Manchester City correspondent Jonathan Smith contributed to this report.
Information from the Press Association was used in this report.