The Blues head coach has revealed how a prized trio are progressing in their respective recoveries from injury
Frank Lampard has delivered fitness updates on Hakim Ziyech, Reece James and Ben Chilwell ahead of Chelsea's clash with Arsenal.
Chelsea are currently preparing for a huge derby showdown against Arsenal at Emirates Stadium on Saturday evening.
The Blues will move into the Premier League's top four if they pick up a second-successive victory against the Gunners, having bounced back from a two-match losing streak by beating West Ham at Stamford Bridge on Monday night.
Arsenal find themselves in a far more desperate situation than their cross-city rivals heading into this weekend's encounter, and will be looking for three points to start distancing themselves from the relegation zone.
Lampard is wary of the threat Mikel Arteta's team will pose, as he labelled the Gunners a "dangerous" outfit with a "class manager" after seeing his side beat the Hammers at the start of the week.
“We've been in decent form [in London derbies] but I don't think we should be taking Arsenal at face value,” he told reporters.
The Chelsea head coach might have hoped he could call upon €40 million (£36m/$49m) summer signing Ziyech at the Emirates, but the Morrocan, who picked up a knock during a 3-1 win over Leeds United at the start of the month, is not quite ready to return to action.
Asked if the 27-year-old will be available for selection against Arsenal, Lampard told a pre-match press conference: "No, he won't be fit for Arsenal."
Pressed on whether or not he is concerned by Ziyech's persistent fitness issues, the Blues legend responded: "No. He had a knee injury at the start of the season and he now has a muscle injury.
"You have to wait to recover. It's not a long-term concern and we hope to have him back in the next week or so.
"And hopefully he can offer what he did before because he was offering great things.
"We missed that in a way but that's football, that's a squad and it's what happens when players are playing at high level every two or three days."
Lampard went on to reveal that James and Chilwell are both doubts for the Arsenal fixture and a meeting with Aston Villa on December 28.
The former missed the West Ham game due to a knee issue, while the latter was withdrawn in the first half after turning his ankle.
"They're both doubtful. We're not sure whether they will be fit for either game," said Lampard.
One man who will almost certainly feature when the Blues make the short trip to Arsenal is Timo Werner, with Lampard adding on a striker who has failed to score in his last nine outings: "I talk to him all the time, I don't sense his frustration, I think it's clear that as a striker you want to be scoring regularly, as he has done in his career.
"But at the same time, every striker has moments when the ball doesn't drop for you for whatever reasons.
"The positive thing is he's getting chances in games, he's using his attributes to get into the box, he's getting chances, so they'll come."