N'Golo Kante is likely to miss Chelsea's game against Tottenham on Saturday after being forced off injured in their 2-0 home defeat to Manchester United on Monday.
The France midfielder was replaced by Mason Mount inside 12 minutes, with Frank Lampard saying after the game he believes Kante has injured the abductor muscle in his leg.
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The head coach told Chelsea's official Fifth Stand app: "N'Golo, after what happened tonight, is probably a no for Saturday.
"It's an abductor injury and we will have to assess him but it doesn't look good at first glance."
Lampard had further bad news on the injury front, revealing Christian Pulisic and Callum Hudson-Odoi will also both miss Spurs' visit to Stamford Bridge.
Pulisic has not played since Chelsea's draw at Brighton on New Year's Day, while Hudson-Odoi was injured following the draw at Leicester before the Blues' winter break.
"Callum is a no, Pulisic is a no," Lampard said when asked about the wingers' availability for Saturday.
He also said Tammy Abraham is "probably a maybe" to face Spurs. Chelsea's top scorer was unable to train fully during the winter break, and missed the loss to United.
As well as losing Kante on Monday night, Chelsea also had to deal with the loss of Andreas Christensen at half-time.
The defender was injured in a clash with Anthony Martial towards the end of the first half, and had only just returned to the pitch following treatment when the forward beat him in the air to head in United's first goal.
Lampard told Chelsea TV: "I felt bad for Andreas. You can definitely give him a bye on the first one because I think he's got a broken nose."
Chelsea's game against Tottenham could have huge ramifications in the race for Champions League football; the Blues are currently fourth, one place and one point ahead of Jose Mourinho's side.