Higuain enjoyed his best run of form under Sarri, scoring 37 goals with the Italian boss prior to moving to Juventus.
According to report from the Stamford Bridge, Higuain is expected to earn about £140,000 a week when he finally joins the club.
Wilson has scored nine Premier League goals this season, with Tottenham's Harry Kane the only English player with more.
By contrast, Higuain netted 38 times in just 42 appearances for Napoli when managed by Sarri in the 2015-16 campaign.
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"He has to make a decision and take on his share of the responsibility", Leonardo said at a press conference on Tuesday.
Sarri has reportedly told the club that he wants Higuain, who is now on loan at AC Milan, having previously worked with the Argentine at Napoli.
Sarri has shuffled his pack around due to the injuries to Giroud and Morata by playing Eden Hazard as the striker in recent games.
On-loan from Juventus, Higuain is wanted by Chelsea - a situation that irks Leonardo.
A World Cup runner-up in 2014, he is also a prolific victor of trophies having claimed three Liga titles with Real Madrid and two Serie A victories at Juventus amid a plethora of cup successes at Madrid, Napoli and Juve.