Kalidou Koulibaly has admitted he hasn't been at his best since moving to Chelsea in the summer. The defender was signed for £33million from Napoli under Thomas Tuchel.
Koulibaly, 31, has made 30 appearances for the Blues this season and had been a regular in Graham Potter's defence prior to his exit. The former Napoli star retained his place under Frank Lampard in the 1-0 loss at Wolverhampton Wanderers too.
Despite his regular appearances in Chelsea's defence, his performances have regularly been criticised. Koulibaly seemed to be at fault for Ellis Simms' late equaliser for Everton before the international break.