The Juventus striker is set to join on loan until the end of the season with the option to extend the deal by a further 12 months.
Higuain was left out of AC Milan’s squad for Monday’s game with Genoa and Gennaro Gattuso criticised him for his decision to leave halfway through his season-long loan from Juve.
And it is understood Chelsea expect the Argentine to arrive in the capital on Tuesday to complete the formalities of his move.
Gattuso said: “I accept his decision. Surely he could have done more and maybe we could have helped him fit in better.
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“I want to be honest with you all. We had a poor training session today due to all these rumours. We spoke after the training session and I did not consider him ready for this game.”
But all parties have agreed to let Higuain cancel his loan at Milan and start one at Chelsea.
Maurizio Sarri is in desperate need of some spark after slamming his players for their mental approach against Arsenal.
Sarri was so furious he chose to speak in Italian through an interpreter after the match to make sure he got his message across.
But Higuain will improve his mood and should offer him a better option up top than misfiring Alvaro Morata.
Morata has struggled this term and has been left out of match squads in recent weeks as he looks set to join Atletico Madrid.
But the pressure is on for Sarri after calling out his players on Saturday evening.
His comments were similar to Antonio Conte’s last season when he began spiralling towards the sack.
Sarri has now decided to go down the route of criticising his players which has seen the likes of Conte, Jose Mourinho and Andre Villas-Boas all sacked by Chelsea in the past.
And former Chelsea striker Tony Cascarino thinks Sarri’s job is now at risk and says he could be sacked if the Higuain deal doesn’t work out.
“I don’t think the system suits everybody at Chelsea and that is the reason I think players are not buying into the way he wants to play,” he told talkSPORT.
“Because he is very determined that he is only going to play this way.
“But unless he has got time – and Chelsea are not a club that will be patient – I think Higuain is going to be his last throw of the dice.
“He has to come in and work. No, you don’t get many chances
“And I have said that Chelsea fans will know what I am saying. I’ve been to games and I have watched them.