Manchester City are sweating on the fitness of star defender Ruben Dias ahead of Sunday’s derby.

Dias was substituted at half-time of Tuesday night’s 2-0 FA Cup victory at Peterborough United with what Pep Guardiola described as a leg injury.

The 24-year-old is undergoing tests and City are awaiting those results before they can ascertain the severity of the problem.

Man City are sweating on the fitness of star defender Ruben Dias ahead of Sunday’s derby

Although Guardiola rotates his team heavily, Dias has started all but three of City’s Premier League games this term and his absence against Manchester United would be a blow to the champions.

Dias is seen as a leader at the back and was voted into the club’s five-man leadership group last summer, taking on captain’s responsibilities if Fernandinho and Ilkay Gundogan are absent.

Nathan Ake was also forced off against Peterborough, with Guardiola set to partner Aymeric Laporte and John Stones together should Dias not prove his fitness. 

Although Pep Guardiola rotates heavily, Dias has started all but three Premier League games

City have not conceded a goal in any of the seven league matches in which Stones has started this season.

Meanwhile, Gundogan revealed on Wednesday that he can envisage signing a new contract at the Etihad Stadium.

‘I am very happy here,’ the 31-year-old told Sport Bild.

‘I love the club and feel extremely comfortable. That’s why I can imagine staying beyond 2023. I still have over a year on contract and am relaxed.’