Sanchez has appeared set to leave Arsenal for Manchester City despite seeing a move to the Etihad Stadium fall through over the summer.
But the Guardian say Manchester United have now attempted to steal a march on their fierce rivals by launching a spectacular £25million bid.
The Red Devils are desperate for more firepower with Romelu Lukaku misfiring in recent weeks and Marcus Rashford and Anthony Martial struggling for consistency.
And they have attempted to deal City a huge blow by landing Sanchez from under their noses.
It is said Pep Guardiola's men have already agreed personal terms with the Arsenal star worth around £250,000 a week, having submitted a £20m offer.
Manchester United have made a £25m bid for Arsenal star Alexis Sanchez
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How Manchester United could look with Alexis Sanchez
Wed, September 20, 2017
Is this how Manchester United could look if they sign Alexis Sanchez from Arsenal?
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Is this how Manchester United could look with Alexis Sanchez?
However, United have bid £5m more and are even willing to better City's wage proposal.
Jose Mourinho is supposedly confident of landing Sanchez despite the player's desperation to work under Guardiola.
The Red Devils are also willing to throw in Henrikh Mkhitaryan to sweeten any deal.
The Armenia international has endured a rocky campaign so far and was recently hooked against Derby at half-time.
Robin van Persie was the last Arsenal star to join Manchester United
Mourinho has always made it clear he believes in the player but Mkhitaryan's confidence appears shot.
Should Sanchez move to United, it is likely to cause much anger among an already-frustrated Arsenal fanbase.
Fans still loath Robin van Persie, who infamously quit the Emirates for United in 2012.
But the Dutchman justified that decision by firing the Red Devils to the Premier League title the following year.
As a result, United are hopeful that, by giving Arsenal the chance to land Mkhitaryan, they can sign Sanchez in return.
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