According to the Mirror's Darren Lewis, Spurs are willing to let the centre-back leave this summer despite the fact there are two years remaining on his deal at the club because a £25 million release clause will activate next year.
Tottenham want in the region of £75 million to let him leave this summer, similar to the fee Liverpool spent to sign Virgil van Dijk in January.
United are among the interested parties, with manager Jose Mourinho hoping to improve his defence this summer.
Sports writer Sam Pilger added the Red Devils could soon have the Belgium international in their grasp:
Alderweireld is one of the best central defenders in the Premier League, so his signing would be a coup for any club that manages to recruit him.
United are sorely in need of a revamp at the back. They started the FA Cup final against Chelsea with a centre-back pairing of Phil Jones and Chris Smalling, both of whom—while impressing at times—have never particularly convinced over a long period during their careers at Old Trafford.
Alderweireld is the epitome of composure in defence, and his distribution helps him effectively build from the back or pick out an attacker with a superb long pass.
Football writer Liam Canning believes the Spurs centre-back would make an excellent capture for United. As does fellow football writer Tom McDermott, but the latter is concerned about the fee that could be involved:
It's understandable Spurs would look to bring in as much as they can for Alderweireld—particularly given chairman Daniel Levy's reputation for being a fearsome negotiator—and United could end up paying around £50 million to get him this summer.
What's more, he's 29, so that further brings into question the value of such a deal.
There are few centre-backs in football better than Alderweireld. However, for that kind of money, United could get someone much younger with the potential to reach a similar level and have funds left over to either spend on other problem positions or to sign the Belgian next year.