The 25-year-old Udinese defender has been watched extensively by clubs all over Europe, after impressing since he arrived in Italy in 2010.
Red Devils boss Sir Alex Ferguson has been credited with an interest in taking Benatia to Old Trafford, as he looks to strengthen a back line that has shipped a whopping 23 goals in the Premier League already this season.
Andre Villas-Boas is also keen to add the highly-rated Moroccan international to his ranks at White Hart Lane, with Spurs stopper Michael Dawson's future in north London still uncertain.
Chelsea's reported interest in Benatia extends back before the interim appointment of Rafael Benitez, whose arrival at Stamford Bridge could spark the end of rumours the Blues want to sign Benatia.
Rated at around £15million, the African is believed to be happy at Stadio Friuli, but in light of Udinese's Europa League exit, he could now be sold in the New Year.
Napoli have made the first move to complete the deal, with the opportunity to remain in Serie A likely to be an attractive proposition for Benatia, meaning a move to the Premier League would seem unlikely in the forthcoming transfer window.