The Argentine, 25, has scored 14 times this season while vying with Karim Benzema for the lead role up front, but it seems a six-year spell at the Bernebeu is now nearing its end.
Higuain's departure would likely see Real enter the market for some high-profile replacements, with Manchester City's Sergio Aguero and Tottenham's Gareth Bale said to be at the top of their shopping list.
And Sanchez has indicated that while Higuain is heading for the exit, Benzema is likely to stay.
"In a great club like real, we believe we need two number nines of a high level," Sanchez said in L'Equipe.
"We have Benzema and Higuain, Higuain will leave, Benzema will stay and two others will come."
Higuain, who joined Real from River Plate in 2007, was linked with Juventus, Paris Saint-Germain and Chelsea in the summer 2012 transfer window.