The Italian discussed the Belgian, after Hazard wasn't given a single minute in the midweek win over Inter Milan in the Champions League.
"He didn't play in the last match as he had a minor knee issue, one that also bothered him in [Friday's] training session," the coach said at a press conference on Saturday.
"We'll see with Hazard, but he has improved in general.
"Yet, we must to be careful with him because of past injuries. To play him in two matches in a row could be difficult.
"He's not yet at the level we all want, but we're all confident that he'll get back to his best."
Gareth Bale is similarly struggling to stay fit and Ancelotti was asked about the Welshman's latest injury, but couldn't provide a date for his return.
"We still don't know how long he'll be out," Ancelotti said of Bale.
"It's quite a significant injury, but it's tough to give a return date.
"It's a shame. He had been playing well."
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