Such news like Chelsea will make an offer for Osimhen in January has been refuted. However it was already meaningless honestly. Because they already have Nkunku even though he is injured. When he recovers they would go on with him and then decide whether there is a need for another striker. But of course we don't know when Nkunku will recover for now. 
I think Chelsea should sign a better goalkeeper rather than signing a striker now. I don't like Robert Sanchez now. He isn't a player who is at Chelsea's level at the moment. Kepa is also not coming back at least until the end of the season and I doubt his future at Chelsea later as well.
Chelsea would make Victor Osimhen their priority signing this summer because they're in need of an attacker. Rumours fast circulating concerning Victor Osimhen having links to join Chelsea next season. The Nigeria international already plan his moves and he's keen on joining an EPL team this coming summer, he lost interest in Napoli following the saga trend few months back when he missed a penalty and the club verified account posted him in transformed mockery video which the Nigerain found to be embarrassing stunt on his reputation and that's a problem the club is dealing with till this present day. I think Chelsea should sign a better goalkeeper rather than signing a striker now. I don't like Robert Sanchez now. He isn't a player who is at Chelsea's level at the moment. Kepa is also not coming back at least until the end of the season and I doubt his future at Chelsea later as well.