#6 Kalidou Koulibaly (Napoli)
Despite being the subject of interest from a bevy of clubs around the continent this summer, Kalidou Kouilbaly stayed put at Serie A club Napoli.
The 29-year-old Senegalese centre-back has been a rock at the heart of the Napoli defence since his arrival at the club in the summer of 2014.
One of the most sought-after players in world football, Koulibaly has earned high praise from Napoli coach Gennaro Gattuso, who recently said in this regard:
"I hope he remains with us, selfishly speaking, because he gives us so much both in technical terms and as a character."
If the 29-year-old continues his good form, Gattuso may not be able to hold on to one of his most prized assets for too long.
#5 Giorgio Chiellini (Juventus)
Giorgio Chiellini may have played only a handful of Serie A games since the start of last season but the Juventus captain, who has been with the Bianconeri since 2005, is a formidable presence in the heart of defence.
The only player with at least one league appearance in Juventus' nine consecutive Serie A-winning seasons, the 36-year-old Chiellini have lost some of his pace but none of his desire to keep out the best of attackers while defending his team's citadel.
#4 Alessio Romagnoli (AC Milan)
Alessio Romagnoli has impressively led AC Milan from the front this season, with the centre-back's exploits at the heart of the defence helping the Rossoneri to the Serie A summit.
The 25-year-old, who has played over 150 Serie A games for Milan since arriving at the club five years ago, has already scored and assisted a goal in this season's competition.
Despite his penchant to get injured, Romagnoli has worked on his fitness and has become a key player in Milan's surge to the top of the Serie A table this season.
"I hope to play another 200 games with Milan," said Romagnoli in a recent interview.