Chelsea want Higuain to replace Alvaro Morata at Stamford Bridge.
A loan agreement that would see the Juventus player move from his spell at Milan to Chelsea is in place.
But Chelsea still need to settle personal terms with the player and complete a medical.
Higuain was expected in London today to complete the formalities of the deal.
But that has so far been delayed because Milan have been working on their own dealings.
Krzysztof Piatek is the man Milan want to replace Higuain and the club would not agree to let the latter leave until the former’s deal had been settled.
And Italian outlet Calciomercato claim Piatek to Milan is all wrapped up.
According to the report, a £31m deal for Piatek to leave Genoa is in place.
Milan have not thrown any players into to agreement.
And it now means Higuain has the green light to board a plane to London.
Whether or not a deal can be done on Tuesday night it remains to be seen.
The latest update on the Piatek deal came through at 17:15, meaning Higuain faces a face against time if he is to sign tonight.
It is more likely that the player will head to London on Wednesday and complete the formalities then.
But Chelsea know he cannot play against Tottenham in the EFL Cup on Thursday unless he pens the deal before 12noon on Wednesday.