MANCHESTER, United Kingdom (AFP) - Manchester City will be unable to do anything to keep highly-regarded midfielder Brahim Diaz if he decides to join Real Madrid the English champions manager Pep Guardiola said on Saturday (Dec 29).

The 19-year-old Spain Under-21 international has been in discussions over a move to the European champions, having become frustrated by a lack of first-team opportunities at the Etihad Stadium.

If the move goes through, it would be the second time in 18 months that City has lost a talented young player who has become frustrated at not playing.

Jadon Sancho left City for Borussia Dortmund in 2017, and has since gone on to make 29 Bundesliga appearances and win three full England caps.

Guardiola claimed he was not aware of how far discussions had progressed between City and Real over Diaz, but a deal is expected to go through in the coming days for a player who is out of contract at the end of the season.

"I don't have any new information on that," said Guardiola at Saturday's press conference on the eve of their match with Southampton.

"I know they are in conversation, but I don't have any new information about the situation. Today (Saturday), he trained with us.

"I was clear last week when I spoke about it. We do everything to keep them (the young players) but they decide."

Guardiola takes his City team to Southampton looking to end a disappointing run of results, with his side dropping to third place in the Premier League after losing three of their past four matches.

The City manager said he saw it as his responsibility to lead the team back to form as they attempt to catch leaders Liverpool, after the disappointment of consecutive defeats against Crystal Palace and Leicester.

"It is a big challenge for me; I have to show whether I'm good or not," he said.

"I wouldn't say I like the situation but I know it's common in football and I like to handle it.

"I will help them and assist them to help each other and we will come back who we are. We will move forward."

City have struggled in the absence of holding midfielder Fernandinho, who missed the defeats by Crystal Palace and Leicester because of injury, and who remains doubtful for the Southampton game, even though he has returned to training.

Guardiola insists he has no plans to change his mind and buy players in January, repeating a statement he made in November.

"I think the answer was clear two times," he said.

"It is still the same."

The manager said he tried to sign cover for Fernandinho before the start of the season, but was thwarted because his targets could not be persuaded to come to the club.

"We tried in the summer but the players don't want to come. What can we do?

"We wait until the end of the window but it didn't happen."