It has been reported that Mourinho wanted to sign the 28-year-old central defender when he was in charge of Manchester United.
The report has also claimed that talks between Tottenham and Napoli over the transfer of the Senegal international have already started.
The former Genk star is reported to be valued at €100 million (£84.16 million).
Good signing for Tottenham Hotspur?
Koulibaly is a brilliant central defender, and the 28-year-old would be a very good signing for Tottenham.
Spurs have not looked great defensively this season, and with Toby Alderweireld out of contract at the end of the season and Jan Vertonghen 32 years of age, the North London outfit do need reinforcements at the back.
Koulibaly is 28 years of age and will not have much re-sale value, but the defender would certainly make Tottenham much better at the back for now.
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