Koulibaly impressed for Napoli last season, having moved from Belgian side Genk in the summer, featuring 37 times in all competitions for the Italian outfit.
29 of those appearances came in Serie A, as he averaged nine defensive actions per match – including 143 clearances and 66 interceptions – while he completed 87% of his total attempted passes.
Despite impressing last term, the versatile defender was left on the bench in Napoli's season-opening 2-1 defeat to Sassuolo at the weekend, which has caused an increase in speculation linking him with an exit.
Norwich manager Alex Neil has signed just four players this summer, with Youssouf Mulumbu, Robbie Brady and Jake Kean arriving on permeant deals and Andre Wisdom coming in on loan.
Therefore, Koulibaly’s arrival would go some way to appeasing the club’s concerned fans. However, Napoli do not need to sell the Frenchman, meaning the Canaries may have to step up their attempts to secure his signature.