Manchester United look great favourites to sign the Chile striker from his London club, in part due to their willingness to pay a bigger transfer fee and offer one of their own as part of the potential deal.
Early reports indicated that this was expected to be Mkhitaryan, but according to the 'Evening Standard', the 'Gunners' want to see if they could include French striker Martial instead with the squad lacking goals up-front.
Sanchez was left out of Arsenal's 2-1 defeat to Bournemouth in the Premier League on Sunday, with Arsene Wenger saying after the match that the player's situation would be resolved "in the next 48 hours."
However, reports also suggest that Jose Mourinho will not entertain the idea of his striker leaving with the Manchester club also struggling to score this season.
Martial has made 20 league appearances, scoring seven times, so is still a highly-valued member of the squad whilst his Armenian team-mate has struggled since moving to Old Trafford from Borussia Dortmund in 2016.
Arsenal could allegedly demand as much as £40m for the 29-year-old but would be willing to agree to a figure in the region of £30m-£35m if a United player was thrown in.