The Premier League giants have been heavily linked with a move for the Brazil international throughout the summer transfer window, the expectation being that a deal would eventually be agreed with their Dutch counterparts.
However, head coach Alfred Schreuder has recently played down speculation of a transfer, a consequence of Ajax having already sold a number of key players in recent months.
Ajax have allegedly also made the decision to increase the 22-year-old's asking price to £84m, a move which effectively ended any possibility of a move materialising before the start of September.
With Erik ten Hag keen to sign at least one creative player, the Dutchman and United are now in a position where they must reassess their list of potential targets.
According to Fichajes, United are contemplating whether to make bids for Rafael Leao, Yannick Carrasco or Pedro Neto.
In the case of Leao, AC Milan are said to be doing everything that they can to agree a new long-term contract with the Portugal international, who has just helped them end an 11-year wait to win another Serie A title.
While two years remain on the winger's contract, a release clause of €120m (£100.77m) is able to be activated, even if it is likely to be beyond United's valuation of the player.
Carrasco also has two years left on his terms at Atletico Madrid and the Belgium international would be available for a much cheaper price than Leao.
That is despite the 28-year-old contributing six goals and six assists from his 34 outings in La Liga last season, the versatile wideman being capable of playing in numerous roles down the flank.
As for Neto, he is currently preparing to try to hold down a place in the Wolverhampton Wanderers starting lineup after missing the majority of the last campaign due to a broken kneecap.
In total, the Portuguese returned to play 466 minutes of Premier League football, contributing one goal and one assist, and the expectation is that he will be first choice at Molineux during 2022-23.
However, despite Neto's long-term contract, Wolves' owners may look to cash in on one of the club's most prized assets before the end of the transfer window, something which has not been achieved through parting ways with the likes of Ruben Neves, Morgan Gibbs-White or Adama Traore.