A swap deal between Chelsea and Juventus is probable now. As far as I have heard Juventus want 40 million euros cash plus Lukaku to send Vlahovic to them. I think this is a quite reasonable deal for Chelsea. There is no meaning in keeping Lukaku for Chelsea in the first place. Vlahovic would be a way better choice at the moment.
Chelsea doesn't agree with such offer. Chelsea already lowered its offer for juventus. The club may agree to get vlahovic once juventus will agree with 35m + lukaku as its offer. It's a non sense deal to give a lot of money for juventus.
Chelsea has been also adding lukaku in the in the its offer. Juventus shall lowered its offer for chelsea if the club is willing to sell vlahovic but the fact that if vlahovic didn't wanna leave from juventus. This deal may be cancelled by chelsea.
Lukaku has played for Chelsea many times and we have never seen him showing an impressive performance consistently. There is no reason to give him another chance. Vlahovic is a young and really skilled scorer. I think he would fit Pochettino's system better than Allegri's.
Juventus and chelsea are so desperate to sell their useless strikers. Vlahovic already made personal agreement with PSG but juventus wants him to be exchanged for lukaku from chelsea + additional funds.
I think that vlahovic can reject it and the transfer will not happen.