In recent days, it has emerged that the Gunners finally accept that Sanchez wants to leave and a battle between United and fierce local rivals Manchester City has been brewing.
City were previously firm favourites to secure a deal after coming close in summer. They have the added bonus of Sanchez previously working with manager Pep Guardiola. But fresh speculation on Friday claimed that the Premier League leaders are cooling their interest.
At the same time, United boss Jose Mourinho described Sanchez as 'phenomenal', seemingly signalling Old Trafford interest in the contract rebel.
Arsenal are understandably holding out for the biggest fee they can get, potentially as much as £35m. But successfully replacing Sanchez is another key condition of letting him go.
The latest on that front is a Daily Star claim that the Gunners have enquired about Martial,
The 22-year-old, who drew comparisons with Arsenal legend Thierry Henry when he first arrived in England, is enjoying a resurgent season after a disappointing 2016/17 campaign. As such the tabloid newspaper suggests United would be unwilling to let him go.
That leaves a cash offer as the only way to tempt Arsenal. City are known to be unwilling to offer more than £20m for a player who can be signed for free on 1st July and are confident that they will get their man because of the Guardiola factor, even if United are willing to pay more.