Kalidou Koulibaly, who was also interesting Juventus, had one year left on his Napoli contract, and his signing follows the £47.5m capture of Raheem Sterling from Manchester City; the defender has penned a four-year deal at Chelsea and has joined up with the club in Las Vegas
The central defender, who has 62 caps for Senegal, has signed a four-year contract worth around £160,000 per week (£8.2m a year) net plus bonuses to move to Stamford Bridge. He flew out to Las Vegas on Friday to join up with his new team-mates on their pre-season tour of USA.
"I'm very happy to be here with this team at Chelsea," Koulibaly said in a statement. "It's a big team in the world and my dream was always to play in the Premier League.