#4 Gary Cahill
Cahill has been a loyal servant to the club since he joined from Bolton in 2012.
The team's captain, he has led by example a lot of times and has offered stability and reassurance at critical times.
However, he had a terrible run in what was a horrible campaign for the team last season. He was too easily beaten by several opponents and was often the weak link in the 3-man centre-back formation favoured by former manager Antonio Conte.
Senegal's Kalidou Koulibaly was a trusted lieutenant to Sarri at Napoli. Chelsea has long admired the towering centre-back and a bid could be put in for his services.
With Sarri favouring a flat back 4 with two centre-backs, it's doubtful if Cahill would get game time over the likes of Christensen, Antonio Rudiger, David Luiz or any new central defensive signing.