#4 Kalidou Koulibaly
For the entire transfer window of last summer, Chelsea chased Koulibaly and failed. With neither David Luiz nor Gary Cahill considered good enough to start regularly, the Blues need a new centre back. The Senegalese is a man mountain of a central defender who also has the ability to pass the ball. He is physically strong and great in the air as well.
Koulibaly has been performing consistently for Napoli over the last four seasons. In both the 2015-16 and 2016-17 seasons he made it to the Serie A team of the year. With his proven quality he would make for a perfect back three with Andreas Christensen and Cesar Azpilicueta. As Napoli manager, Sarri blocked Koulibaly's move to Chelsea but will he now be able to convince him to move.
#3 Dries Mertens
In recent times Chelsea have been a club with strong Belgian representation. Even though they let go off talents like Romelu Lukaku and Kevin De Bruyne, they still have Hazard, Courtois and Batshuayi in the team. Dries Mertens could be another addition to the Belgian contingent at Stamford Bridge.
With Pedro`s best behind him and Willian also ageing, Mertens would provide options on the wing. In the ongoing World Cup Hazard and Mertens are playing together on the wings for Belgium and Chelsea would hope that they are able to replicate the same chemistry for club as well. While Mertens is also 31, his recent form with Napoli has been far better than that off Willian or Pedro.
Sarri might be tempted to make Mertens his first signing and hope that the Belgians come together to power his team to success.