The easy option for Kalidou Koulibaly last summer was to stay with Napoli. He was a club legend, viewed as one of Serie A's standout central defenders, and his family was firmly settled after eight years in the vibrant Italian city. Yet the lure of playing Premier League football – and for Chelsea – proved too much.
A deal worth £33.8million was swiftly concluded and Koulibaly joined his new teammates during their tour of the United States. The hope on the part of Chelsea, and then-head coach Thomas Tuchel, was the Senegal international would prove a worthy replacement for Antonio Rudiger.
Koulibaly knew that would not be easy. After almost a decade in Italy, an inevitable period of adaptation would be required. Mistakes would be made along the way. "I will have to adapt everything because the speed is faster in the Premier League," the 31-year-old said at his unveiling press conference.
