Chelsea summer signing Kalidou Koulibaly spoke to both Didier Drogba and Gianfranco Zola before sealing his transfer from Napoli.

The Senegal international was the big money defensive signing by the club's new owners, and was eventually joined by Wesley Fofana late in the window.

Koulibaly, who had long been linked with a Premier League move, admits he spoke to club legends about the team and England in general before committing to the transfer.

While talking to Corriere della Sera, Kouliably said, "[Managers Thomas and Graham] Tuchel and Potter play with a three-man defence, and I was accustomed to playing with four defenders in Naples. One never stops learning. I knew I'd have struggled at the beginning, Zola and Drogba had told me."

He added: "[The Premier League is] The best in the world, not as tactical but more intense. You have to get here after playing in Italy, Thiago Silva and I talk about tactics in Italian.

"I don't know if it was the right choice. It is different for strikers, but defenders need the Italian school of tactics. It's mandatory."