Former Chelsea manager, Rafa Benitez has said Kalidou Koulibaly could struggle to adapt in the Premier League following his move from Napoli.
The 31-year-old has spent eight years in Serie A, but has now sealed a move to Stamford Bridge.
Blues boss, Thomas Tuchel, has brought in Koulibaly after losing Antonio Rudiger and Andreas Christensen this summer.
But Benitez, who managed the Senegal defender at Napoli, fears his adaptation process is unlikely to be a smooth one.
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.
“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.
Aerial ability wasn’t his biggest strength but in Italy that mattered a bit less and he was ok.
“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.”