........... But precisely at this time the clause and the high price are a barrier for Osimhen to leave and when Napoli needs money to recruit Lukaku from Chelsea, if Osimhen leaves automatically Lukaku will be the main target to replace him, but I think it will be a big gamble for Napoli later, indeed so far Lukaku has performed quite well if he plays in Serie A but we cannot be sure if he will be very effective to replace Osimhen role at Napoli Later, besides that Lukaku old age, of course, it is only possible if Napoli signs him in the short term..
It is actually depending on the board of Napoli itself. If they want to lower the transfer fees of Osimhen, it won't be so difficult to sell Osimhen. PSG agrees to sign Osimhen at €120 million, it is a huge money. If Napoli is serious to sell Osimhen, they must agree with €120 million. Unfortunately, it is rumored that Aurelio De Laurentiis wants Osimhen to stay in team, that's why he set huge transfer fees. As far as I know, he wants €150 million if PSG wants to get Osimhen.
If Napoli is serious to sign Lukaku, they won't pay for a very expensive price. Chelsea only sets a minimum price at €29m - €30m. I think Napoli has the money, I don't know why they must sell Osimhen to sign Lukaku. If they want to sell the current players, they can sell other players. There are Giacomo Raspadori and Giovanni Simeone who can be the options to put on the transfer list. If Napoli succeed to sell these players, it is enough to pay the minimum price of Lukaku.