Maurizio Sarri was right to question his Chelsea players, including N'Golo Kante, after the defeat to Tottenham last week, according to Willian.
Chelsea's unbeaten start to the Premier League season ended with a 3-1 defeat at Wembley, in which they were 3-0 down after only 54 minutes.
Sarri was far from pleased with his side's display and this week criticised Kante specifically for failing to stick to his position to the right of Jorginho in the three-man midfield.
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The decision to single out one of Chelsea's star performers over the past two seasons was a surprise, but Willian insists all the squad need to sharpen up.