Milan paid 18 million euros ($20.75 million) to sign him on loan, with a clause to make the deal permanent for a further 36 million euros.
The 31-year-old, who is now on a season-long loan at Milan from Juventus, wants to cut short his time at the San Siro and reunite with Maurizio Sarri.
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They likely are interested in him with the hope he could groom quarterback Sam Darnold the same way he did with Aaron Rodgers. The former first-round pick threw for 2,865 yards, 17 touchdowns and 15 interceptions in 13 games during his rookie campaign.
He previously spent six years at Real Madrid before starting his career at River Plate in Argentina.
He was hampered by a back injury earlier in the season but broke a two-month goal drought just before the winter break.
Milan's sporting director Leonardo however warned on Tuesday he had to get down to work.
Brazilian Leonardo added: "There's no point following rumours and gossip".
Father-figure Sarri will believe he is the man to get the player firing on full cylinders after his prolific spell in Naples saw him hit 71 goals in 104 appearances, and will believe a rejuvenated Higuain can fire Chelsea to a top-four finish in the table.