Sanchez was expected to seal his move to Manchester City next summer, but United's intervention may be an attempt to change the tide of momentum flowing towards their local rivals in a season when they are running away with the Premier League title.
Prior to the match against Bournemouth, Sky Sports conducted an interview with Wenger and the Arsenal manager was asked if the Arsenal fans can accurately say that his decision to drop the Chilean is to finally get a resolution to the situation, one way or another - he leaves or stays.
And, although Wenger gave no clues as to where Sanchez will end up, he believes movement on the matter will come soon after he left the attacker at home for Arsenal's trip to Bournemouth on Sunday.
Wenger said: "Yes. Don't read too much into it though because not even I know which way it will go".
So, when it emerged Sanchez has been left out of the squad, United supporters were quick to express their excitement on Twitter...
But despite United's apparent eleventh-hour move for Sanchez, sources have told ESPN FC that the club has been quietly attempting to beat City to the player since last August. "These guys want to win, and they want to make money as well".
But with Arsenal pulling the plug on a £60m sale of Sanchez to City on the final day of the window due to their failure to sign a replacement, United have since explored the possibility of signing him. Incidentally he's won trophies with us.
The 29-year-old Chilean will be entering his potential new club who lead the Premier League by 15 points over his other suitors United.