Jose Mourinho opted to go big on Romelu Lukaku last summer and the brawny Belgian has enjoyed a relatively successful first season to date; netting 20 goals and five assists in all competitions.
However, the report claims the 24-year-old's shortcomings against the top four this season will cost him dearly, with United set to break the bank once again to sign the Premier League's top scorer; in a deal that would likely see Kane become England's record signing.
The source claims the Red Devils are prepared to offer more than double the English international's current weekly salary - £100,000 - to secure his services from Spurs and stave off competition from the likes of Real Madrid.
Los Blancos are likely to undergo a squad revolution during the summer and they're reportedly aiming to sign Kane as a replacement for the struggling Karim Benzema.
Kane's affinity with Spurs is known to be largely down to his relationship with current manager Mauricio Pochettino, but the Argentine coach has also been linked with a move to the Bernabeu next season.
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Having established himself as one of the world’s best forwards, picking up two Golden Boots -and favourite in the running for a third - Kane's motivation may very well turn from personal accolades to winning trophies, and that would see United in with a thread of hope of securing the player's services.