Champions League: Manchester City will be without Aleksandar Kolarov for the next month

Aleksandar Kolarov: Picked up injury ahead of the Manchester derby

Manchester City defender Aleksandar Kolarov is facing at least a month on the sidelines due to a calf injury.

And City will also be without Frank Lampard for Wednesday’s crucial Champions League tie at home to CSKA Moscow, although the midfielder could return at the weekend.

Serbia international left-back Kolarov was injured in the warm-up ahead of Sunday's 1-0 derby win over Manchester United at the Etihad Stadium.

And he is set to miss Champions League matches against CSKA Moscow and Bayern Munich, as well as Premier League fixtures against QPR, Swansea and Southampton this month.

Aleksandar Kolarov has been ruled out for a month with a calf injury, while Frank Lampard is out of Man City's Champions League match against CSKA Moscow Aleksandar Kolarov has been ruled out for a month with a calf injury, while Frank Lampard is out of Man City's Champions League match against CSKA Moscow

"Kolarov has a muscle injury in his calf," said Pellegrini. "He will be out for at least one month.

"Well, I am not a doctor, but I suppose that."

Gael Clichy replaced Kolarov for Sunday's derby success.

Lampard was believed to be in contention for the CSKA encounter but will remain on the sidelines with a thigh injury and David Silva continues to recover from a knee problem.

However, defender Eliaquim Mangala has been passed fit for the match, as City look for their first Champions League win of the season.

“Mangala has just stiffness in his hip so he is in the squad list,” said Pellegrini. “Frank, I think he will be fit next week."

The 36-year-old Lampard has made a big impact, having joined on loan from sister club New York City until January.

But Pellegrini again refused to be drawn on whether City might seek to extend the midfielder’s stay at the club.

"Frank Lampard is injured so, when he recovers, we can talk about that issue,” said the manager.

"I talked about it two months ago. We can see what happens in December, we have until December to decide."

Watch Manchester City's Champions League Group E clash at home to CSKA Moscow live on Sky Sports 5 HD on Wednesday night, with coverage underway from 6pm.