The Premier League title-holders have been hit by injury problems and poor form as they trail leaders Liverpool by 12 points.

Manchester City need to invest during the January transfer window due to injury problems and a faltering Premier League campaign, manager Pep Guardiola has said, acknowledging it may have been a mistake to rule out signings in the summer.

“In the summer the club thought about [signings] and I said: ‘No, I don’t want to make any signings,” Guardiola told reporters on Monday.

“I relied a lot on these guys and thought I can do it again. But after the injuries maybe we should have done it.”

City’s title defence looks all but over after six league defeats have left them sixth in the standings and 12 points behind leaders Liverpool who have a game in hand.

Guardiola’s side have missed Ballon d’Or-winning midfielder Rodri, who ruptured knee ligaments in September, and have suffered injuries to defenders John Stones and Ruben Dias.

City have not made a significant signing in January since the arrival of Aymeric Laporte for $69.67m from Athletic Bilbao in 2018.

Guardiola could not confirm whether a deal has been done to bring in Lens defender Abdukodir Khusanov.

“The club didn’t announce anything. I don’t know,” he said.

“Rodri is impossible but the other ones [injured players] I want back. If it would have happened I wouldn’t be going to the transfer window this season. Absolutely not.

“We would not be in the position that we are but we struggle all season. It’s not just Rodri, we have a lot of problems in the back four. That is the reason why the club is thinking we might do this transfer.”

After City’s 8-0 FA Cup win over Salford City on Saturday, Guardiola revealed that Walker had asked to leave the club, but the manager had no update on the situation and the right-back could be in the squad at Brentford.

“No news. I’m not going to add anything, no more news. I only have Brentford on my mind,” Guardiola said.