I'm very sorry for Lukaku, he's a player I really like and appreciate for his mentality and his physicality, he's great and I think that without him Napoli could suffer and not a little, I also believe that they won't find a replacement easily, now they have to adapt more than ever
Lukaku is likely to miss the first game of the season which is an away one against Sassuolo. In his absence, Lorenzo Lucca would take his place in the starting lineup I assume. This is indeed sad news especially for Conte.
You know Lukaku is his beloved player in the squad. But thankfully it isn't a serious injury at least. As Napoli hasn't signed another striker, they will continue to rely on Lukaku in the CF position... Let's see how good duo they will make with De Bruyne there.