Thomas Tuchel sets Kalidou Koulibaly target after Rafa Benitez raises major concerns

Chelsea boss Thomas Tuchel has set a target to new £34million signing Kalidou Koulibaly after former Blues boss Rafa Benitez raised concerns over the Senegalese centre-back.

Tuchel’s side completed their second signing of the summer in the early hours of Saturday morning, bringing in the defender from Napoli on a four-year contract. The 31-year-old has travelled to America to link up with his new teammates for their pre-season friendlies.

However, concerns over how Koulibaly will suit the Premier League have been raised by Benitez, who also managed the defender at Napoli during his short stint in Naples between 2013 and 2015.

Benitez believes the defender must improve his concentration and his aerial ability in order to reach the levels Chelsea will hope to have him at after signing him as a replacement for Antonio Rudiger and Andreas Christensen.

Discussing Koulibaly, the Spaniard 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