The Red Devils completed a deal for Leny Yoro last week, with the 18-year-old arriving from Lille, but it is believed that Erik ten Hag's team are keen on bringing a second centre-back to Old Trafford this summer.
De Ligt is thought to be a leading target for Man United, with the Netherlands international previously playing under now Red Devils manager Ten Hag at Ajax.
However, according to German journalist Florian Plettenberg, the English club's offers for the 24-year-old have thus far not met Bayern's valuation.
Plettenberg, via X, claims that the 20-time English champions "are offering significantly less than €40m (£33.6m)", with Bayern not prepared to be pressured into a sale despite being open to his exit.
Man United 'are not meeting Bayern's valuation'
Man United must allegedly pay €50m (£42m) plus bonus payments if they wish to sign the former Ajax youngster, and Bayern are not willing to negotiate.
The Red Devils had seemingly be on the verge of closing a transfer for De Ligt before their attention switched to securing a deal for Yoro, who was also heavily being linked with Real Madrid.
Raphael Varane's departure on a free transfer meant that Man United were always going to move for one centre-back this summer, but Victor Lindelof is also being linked with an exit, so it is entirely possible that another player will arrive in that area of the field.
Everton's Jarrad Branthwaite could prove to be too expensive, but the Red Devils will allegedly have to raise their bid for De Ligt if they are to secure his signature this summer.
Would De Ligt be a good signing for Man United?
De Ligt, Yoro and Lisandro Martinez would be an impressive centre-back trio to choose from next season, while Harry Maguire is also set to stay at Old Trafford despite the speculation surrounding his future.
Jonny Evans has penned another contract, so the Northern Ireland international will provide support next term, with Willy Kambwala following Varane out of the door this summer.
De Ligt starred at Ajax in the early stages of his career, winning a league and cup double during the 2018-19 campaign, before making the move to Juventus, and he left the Old Lady having lifted three trophies, including the Serie A title.
The defender has had more success at Bayern, winning the Bundesliga and DFL-Supercup, and he has featured on 324 occasions during his professional career.
Even for €50m (£42m), De Ligt would be a bargain, but Man United must sell before they can bring him in, and exits for the likes of Lindelof and Aaron Wan-Bissaka would make space for his arrival.