Kalidou Koulibaly: How does Senegal Superstar fit in Chelsea FC?

After a successful eight-year run in Serie A with Napoli that included a 2020 Coppa Italia title, center back Kalidou Koulibaly is on his way to Stamford Bridge. The news arrives only days after Chelsea completed the signing of prolific English attacker Raheem Sterling from Manchester City.

The move greatly assists the Blues in their plans to restructure their back line after Antonio Rudiger and Andreas Christensen left the club on free transfers. A series of reports point to the club hoping to sign Nathan Ake, Presnel Kimpembe, and Jules Kounde to revamp the defense further.

A Senegal international who was part of the squad that won the 2021 Africa Cup of Nations, Koulibaly joins Chelsea on a transfer fee of €40 million (just under $40 million) including add-ons; insider Fabrizio Romano reports that he'll receive a €10 million salary per season over five years, though the length of the contract has yet to be confirmed by the club.

Let's establish everything you need to know about Koulibaly's transfer to Chelsea and how he fits seamlessly into the club's defensive plans under Thomas Tuchel.

Kalidou Koulibaly: Contract & Transfer Details

Reported contract length: 5 years

Expected weekly wages: $191,400 (€192,300)

Expected annual wages: $9,955,000 (€10,000,000)

Free agency: 2027

Base transfer fee: $37,829,000 (€38,000,000)

Max transfer fee: $39,820,000 (€40,000,000)

Estimated market value: $38,500,000 (via Transfermarkt)

How Koulibaly Fits in at Chelsea:

Chelsea's best teams over the past 20 years have all featured strong, dynamic defensive groups. Amid some roster tunrover, Thomas Tuchel and new Chelsea owner Todd Boehly are working to realize that standard once again.

Last season, Chelsea primarily ran a 3-4-3-1 with a back three of Rudiger, Thiago Silva, and César Azpilicueta. Rudiger left the club on a free transfer to Real Madrid, while both Silva and Azpilicueta are closer to the end of their careers than the beginning at ages 37 and 32 respectively.

Meanwhile, Napoli primarily ran formations that featured a back four, with Koulibaly slotted as the right center back. On the only occasion in which Napoli deployed a back three, he was featured as the anchor in the middle. Without bringing Ake, Kimpembe, and Kounde on board, Koulibaly will more than likely earn his minutes as the middle stopper. At age 31, he's fast, strong, wins the ball, and asserts himself at an elite level in the air.

The signing of Koulibaly is the first step toward coalescing Chelsea's defensive plans for 2022-23 and beyond. If they land each of their desired targets the rest of the summer, expect them to be in the mix for another top-four spot in the Premier League.