But, United chief David Moyes is keen to beat his rivals to the 24-year-old with a winter swoop.
The Scot has been promised serious funds to build his squad after a botched summer of transfer activity, and sees Reus as the perfect man to kick-start his Old Trafford reign.
A £25m offer is thought to be on the cards, with chief executive Edward Woodward said to be putting the wheels in motion.
Dortmund are thought to be far from keen to let the wide-man leave, but United are willing to tempt them by throwing in Shinji Kagawa as part of the deal.
The Japanese playmaker moved to England from the Westfalenstadion last year, but is thought to be ready to return after falling out of favour.
Meanwhile, a centre-back is also thought to be a priority for Moyes.
Benfica’s Ezequiel Garay – who was linked with a move to the club during the last window – is thought to be his top target.
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