Lukaku was deemed surplus to requirements by then Chelsea boss Jose Mourinho and offloaded to Everton for £28-million (R616-million) ahead of the 2014/15 season.
He has been a hit at Goodison Park, scoring 45 goals in two seasons, and it looks as though Chelsea will have to admit to a very expensive mistake.
Lukaku has already expressed his desire to leave Everton in search of UEFA Champions League football and if the price is right, Everton will not stand in his way.
But there could also be a late twist to the tale with new Manchester United manager Mourinho said to be keen to take him to Old Trafford having realised the folly of his ways.
Lukaku has also been tipped as a replacement for Zlatan Ibrahimovic at Paris St Germain, and is also said to be on the wanted list of Bayern Munich.