Kalidou Koulibaly told he must ‘improve his concentration’ to succeed at Chelsea by Rafael Benitez

Former Chelsea manager Rafael Benitez has admitted Kalidou Koulibaly must improve his concentration levels ahead of playing for the Blues. 

The defender has completed a £34million switch to Chelsea from Napoli and is expected to fill the void left by Antonio Rudiger, who has joined Real Madrid on a free transfer.

But Benitez, who managed Koulibaly during his time as Napoli boss, has shared his concerns over the defender losing focus on the pitch and his tendency to be ‘overconfident’.

These worries have left the former Blues manager doubting whether the 31-year-old will be as dominant as he was in Serie A. 

Senegalese defender Kalidou Koulibaly joined Chelsea from Napoli in a deal worth £34million 

Rafael Benitez managed Koulibaly when he was manager of Italian outfit Napoli

He told The Athletic: ‘He must improve his concentration at times.

‘He can be guilty of losing focus and can be overconfident, but he has been hugely influential at Napoli and people I know and trust have told me that he has been the best centre-back in Italy during this time.

‘This season will be the Premier League for him and he could be fine for the way that Tuchel wants to play.

‘He has similarities with Rudiger – he is very good at running with the ball, he’s good with both feet.’

‘Powered by “is he a little bit too nice?” We will see what happens at Chelsea.

‘As I said, in Italy he was fine because he was so quick, but I doubt he will be so dominant over here.’

Koulibaly has been signed by Chelsea as a replacement for Antonio Rudiger, who has joined Real

Benitez has also suggested that while Koulibaly’s aerial ability was not the best, he was always willing to try and improve and take on advice from the coaches. 

‘Aerial ability wasn’t his biggest strength but in Italy, that mattered a bit less and he was ok,’ he said.

‘It will be interesting to see how that develops in the Premier League but he was always very keen to learn.

‘He spent time with me and my staff after training sessions to work on his heading and improving his technique.’  

Chelsea boss Thomas Tuchel has been trying to sign Koulibaly all summer as he needed defensive reinforcements following the exits of central-defenders Rudiger and Andreas Christensen, who joined Barcelona after his contract at Stamford Bridge expired.