Frank Lampard admitted Chelsea have missed Hakim Ziyech following the 1-1 draw against Aston Villa.
Ziyech was in fine form before suffering a hamstring injury and the Blues have struggled without him.
Having lost three of their previous four games, they were much improved against Villa but still dropped points.
It has been a tough spell for Chelsea and boss Lampard said: “I don’t think it’s a coincidence.
“Hakim, with the way he was playing, was being very effective for us and had a real confidence in the way he was playing. It helped that we were very fluid at the time.
“It has been a point. You’re going to miss players of that level when they drop out.”
Ziyech could be available against Manchester City this weekend, although there is doubt over whether that game will go ahead given that a Covid-19 outbreak in the City camp led to their match against Everton being called off.
Lampard said: “We want him back. Where is he at? There’s a possibility he could be fit for Manchester City if it goes ahead on Sunday.
“I’ll know later in the week, but he’s certainly progressing to the point where he’s very close to fitness.”
Lampard made six changes for the Villa game, including restoring captain Cesar Azpilicueta in place of Reece James at right-back.
James, who has had a knee injury recently, is now nursing a hamstring problem.
Lampard explained: “Reece James has a small hamstring issue.
“I’m not saying that’s why Azpi played. I probably would have played him anyway.”