Kalidou Koulibaly is the subjected of a failed €100m (£89.2m) offer with Manchester United reportedly keen.
The Senegalese international shone at the 2018 World Cup in Russia and is seen as one of Europe's finest centre-backs.
Chelsea have previously been fended off by Napoli and now an unnamed club has also been knocked back.
With Calciomercato claiming that club is Manchester United, with Jose Mourinho desperate for defensive reinforcements.
Mourinho is dissatisfied with Eric Bailly, Chris Smalling, Phil Jones and Victor Lindelof as a collective and Koulibaly would certainly strengthen his defence.
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Chelsea
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Napoli
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Koulibaly
Udeh Nzube
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I don't believe this story coulibaily is a central defender like we don't need him yapp have a 100m for coulibaly but don't have 60m for Alex Sandro