The centre-back will line up for the Serie A side against Arsenal in the Europa League tonight.
Koulibaly has impressed this season and has been linked with a Napoli exit all year.
Manchester United boss Ole Gunnar Solskjaer will look to strengthen his side this summer with a central defender high on his wish list.
But Koulibaly has insisted he is focused on the fact he is a Napoli player until the end of the season.
He said: “The future?
“I am a Napoli player and I will give one hundred percent to win something with this shirt.
“The market is full of talk.
“I prefer facts, which then help us win and become great together.”
Former United manager Jose Mourinho was also keen on signing Koulibaly.
And Solskjaer is reportedly willing to pay £100million for a central defender this season.
Raphael Varane is the top target for United but persuading him to leave Real Madrid is a tall order.
That makes Koulibaly the most likely acquisition for Solskjaer as he rebuilds the side he inherited from Mourinho.
The 27-year-old will hope to impress for Napoli tonight and turn round a deficit from the first leg against Arsenal.
The Gunners lead 2-0 on aggregate after an impressive display last week at the Emirates.
Napoli vs Arsenal kicks off at 8pm this evening.
The winners of the match will play either Villarreal or Valencia in the Europa League semi-finals.