The Red Devils have been in lengthy negotiations with Barcelona over De Jong, and it is understood that a "broad agreement" has now been reached, with all parties confident that the deal will soon be confirmed.
Malacia, meanwhile, is also seemingly heading for Old Trafford, with Man United agreeing a deal with Feyenoord for the left-back, who was believed to be on the verge of joining Lyon.
New head coach Erik ten Hag is still believed to want at least another three signings, though, as he looks to put together a squad capable of challenging higher up the Premier League table next season.
With that in mind, Sports Mole picks out three players that could follow De Jong and Malacia to Old Trafford this summer.
Lisandro Martinez is a player in demand this summer, with Man United and Arsenal both believed to be interested in signing the Argentina international during the current market.
The 24-year-old - thought to be valued by Ajax in the region of £45m - was a key player for his Dutch club during the 2021-22 campaign, contributing one goal and four assists in 36 appearances in all competitions.
As a result, Martinez is now thought to be the club's leading defensive target, with Ten Hag keen on a reunion with the player that he managed in Amsterdam.
Ajax are not under any real pressure to sell the South American this summer, though, so Man United face a task to bring him to Old Trafford ahead of the 2022-23 campaign.
Man United are believed to have offered Christian Eriksen a contract, with the 30-year-old allegedly making the decision to leave Brentford on a free transfer at the end of the month.
Eriksen is said to be on the verge of making a decision on his future, and the 20-time English champions are thought to be in a strong position to bring him to Old Trafford.
The Denmark international impressed for Brentford in the second half of the 2021-22 campaign, scoring once and providing four assists in 11 Premier League appearances.
Ten Hag is believed to view Eriksen as a key part of his plans moving forward, but the playmaker recently said that he has a number of offers on the table.
The attacker had an implantable cardioverter defibrillator device fitted after suffering a cardiac arrest at Euro 2020, which saw him leave former club Inter Milan.
Antony was in excellent form for Ajax during the 2021-22 campaign, scoring 12 goals and registering 10 assists in 32 appearances in all competitions.
The 22-year-old has allegedly been identified by Ten Hag as a leading summer target, but Man United will reportedly have to pay £80m to bring the Brazilian to Old Trafford.
Antony largely plays as a right-sided attacker, which has been a problematic position for the Red Devils in recent years, and the club need to boost their forward line this summer following the departures of Jesse Lingard, Juan Mata and Edinson Cavani on free transfers.
Ajax have the South American on a contract until June 2025 and are prepared to be put up a fight to keep hold of him, but Man United could concentrate their efforts on the attacker once they have confirmed deals for De Jong and Malacia.