Kyle Walker underwent groin surgery; no timetable for his potential return has been set, but Manchester City believe he still has a chance to play in the World Cup.

Kyle Walker is a doubt for the World Cup in Qatar, according to Manchester City, who confirmed the full-back had "successful" groin surgery.

Walker was injured during City's 6-3 derby victory over Manchester United at the Etihad Stadium on Sunday. Walker came into the game with a groin ache that worsened during the game, and he was replaced just before halftime.

There is no timetable for Walker's return, but it is understood that both Man City and Walker believe the right-back has a chance to play in the World Cup.

Walker, 32, has a reputation for being a "quicker healer" after previous injuries, but his availability will be determined by how his body reacts to the operation, with the next two weeks crucial.

Walker tweeted a photo of himself after surgery with the caption: "As players, we must accept that injuries are an inevitable part of the game we love. My surgery on Tuesday went well, and now I can focus on my rehab and getting back to full fitness. Every day, I will do everything I can to help my teammates."

Man City decided to have the surgery now because of Walker's speed and the fact that the injury cannot be managed while he is still playing.

Gareth Southgate is expected to name his Qatar 2022 squad on October 20, well ahead of FIFA's deadline of Sunday, November 13.

England will play Iran in their first World Cup group game on November 21 at the Khalifa International Stadium in Doha, the same venue where Germany will kick off their Qatar 2022 campaign on November 23 against Japan.

Pep Guardiola insists Erling Haaland's contract contains no release clause and that the Norwegian striker is "settled" and "happy" at Manchester City.

According to reports in Spain, the 22-year-contract old's may include a clause that allows him to join Real Madrid in two years or for a lower fee than other clubs.

Before Man City's 5-0 win over FC Copenhagen, in which Haaland scored twice, bringing his season tally to 20 in 14 games, the club denied those reports, and Guardiola reiterated the club's stance in his post-match press conference.

"It's not true," said the Spaniard. "He has no release clause with Real Madrid or any other club. All I can say is that it is not true. People gossip, and we have no control over it. We must always be concerned with what we can control.

"He adjusted very well, and I have the impression that he is very happy here. We will do our best to make everyone who wants to stay happy. That is the most important consideration.

"In the end, no one knows what will happen in the future. What matters is that he is perfectly settled here, that he is happy, and that he is adored by everyone. This is the most crucial point."