The £18million summer signing from CSKA Moscow has so far been limited to just two appearances this season, and is still to feature in the Barclays Premier League.

With left-back Ashley Cole out injured, the versatile 25-year-old could be set for a run in the first team - provided he can get match fit.

Zhirkov is currently away with Russia as they look to secure World Cup qualification against Slovenia tonight.

On his return to Stamford Bridge, Zhirkov hopes his fitness situation will improve.

"I try to remain optimistic: many players have had such difficulties. I am not the first, not the last," Zhirkov said in Russian newspaper Sport Express.

"It is a pity that the problems coincided with my move to a new club, but if I keep being distressed the situation will not change.

"I must work and believe that everything is going to straighten out soon.

"In Chelsea the team is very good, all of them understand my situation.

"My case is not the first one, many newcomers of Chelsea were sidelined in the first months in the club."

Zhirkov revealed a change in climate or even diet could be behind his knee problems, with swelling causing him pain after aggravating an old injury during the pre-season friendly against AC Milan.

"The English doctors see my problems as a reaction of the body to drastic changes - in the climate, lifestyle, training work and in everything else," Zhirkov added.