Chelsea assistant manager Gianfranco Zola has sympathy with out of favour defender Gary Cahill over a lack of game-time at the club this season.

The defender, whose contract expires at the end of the season, had not featured this campaign before playing 21 minutes off the bench at West Ham on Sunday.

"It is totally understandable Gary is upset and we want him to be upset. It means he cares," former Chelsea striker Zola said.

"He has been a top professional; he is doing everything correctly."

Cahill, who stepped aside from England duty in August, joined Chelsea from Bolton in January 2012.

Zola suggested Cahill could feature in the Blues' Carabao Cup third-round tie against Liverpool on Tuesday.

"He needs to be patient because he came late, and the players that were already here did very well," Zola said.

"He will have his chances, then it's down to him to take those chances in the best way."