Ziyech has been out due to an injury and since then Chelsea have just won one of six games and Frank Lampard is desperate to have him back.
said that it is not a coincidenceChelsea
's form has slumped since
injured but the head coach believes there is a chance that the Moroccan is fit to face Manchester City.
Lampard is aware of the Moroccan’s effect on his side and he insists they must be more creative and don’t just rely on the former Ajax star.
"Not a coincidence. We can't rely completely on him. He was very effective of us in terms of creation and goals,"
the coach said when asked the significance of the Morocco international's absence
"It helped, we were very fluid until he got injured. We want him back. There's a possibility he could be fit for [Sunday's game against] Manchester City if it goes ahead. He's close."
The blues manager also talked about their disappointing result against Aston Villa on Monday.
"It's a draw against a good team. Our performance was good and we deserved to win. We've come through a difficult patch. We saw the attitude of the team today. The table is still tight and we remain close. Today I saw some good signs I like."
Chelsea face City at Stamford Bridge on January 3.