Easy cop out saying who could replace him. Probably dozens of players round the world.
The other belgium striker chelsea have bought was available for 7mil a year ago now hes a 30mil player. Im pretty sure there are players out there who could replace lukaku who havent played for a top club yet so havent had the exsposure.
but, that doesn't mean you let your best player leave. one who guarantees goals...
you get a decent back-up in this summer who hopefully proves they can fill the void when Rom does leave.