Napoli vice president Edoardo De Laurentiis remains hopeful of tying Kalidou Koulibaly and Dries Mertens down to new contracts, although he is uncertain why the former is yet to commit his future to the Partenopei.
Meanwhile, De Laurentiis has refused to rule out a move for free agent Paulo Dybala after the talented Argentinian left Juventus.
Napoli enjoyed a promising first season under Luciano Spalletti last term, finishing third in Serie A after threatening to win a first Scudetto since Diego Maradona starred in their 1989-90 triumph.
Both Koulibaly and Mertens played key roles for Spalletti's men, with the Senegal captain helping Napoli concede the joint-fewest goals (31) and keep the second-most clean sheets (16) in Serie A.
Mertens, meanwhile, scored 11 league goals last term, a figure only bettered by Victor Osimhen (14) among Napoli players.
But having already lost Lorenzo Insigne to Major League Soccer team Toronto FC in the off-season, Napoli are yet to agree fresh contract terms with either of their star duo.
Koulibaly has just one year remaining on his deal, and De Laurentiis is keen to see him extend his eight-year stay with the club.
"We offered him €6million net per season for the next 5 years, I don't know what to tell you better than this," he said.
"Why hasn't he accepted yet? I can't get into every single player's head.
"What we have offered him is not cheap, especially after the pandemic. Koulibaly is a great man and over the years he has proven to be a great person, for us to confirm him is the most important thing in the world."
De Laurentiis is more hopeful of reaching an agreement with the club's record scorer Mertens, who has been out of contract since the end of last month.
"We also offered him a very important figure," De Laurentiis said, referring to the Belgium international.
"We offered him €2.5m net and for me he will accept, Naples is a city that has given him a lot and can still give him a lot. In life we must always be positive."
Meanwhile, the loss of Insigne has led to speculation Napoli could rival other Serie A clubs for Dybala's signature, and De Laurentiis has refused to rule out making an offer to the 28-year-old, despite sporting director Cristiano Giuntoli claiming the attacker was "out of reach" on Saturday.
Asked about Dybala, De Laurentiis quipped: "Who knows? The ways of the lord are infinite."
Napoli begin their 2022-23 Serie A campaign with a trip to Hellas Verona on August 15.