United are in talks with Barcelona over the midfielder and a fee of £56m has been agreed, with personal terms explained.
United finished sixth in the Premier League last season and failed to qualify for the Champions League, a competition the 25-year-old is keen to take part in.
Watchman Chelsea’s claim is watching the situation and waiting to pounce.
Thomas Tuchel’s side have yet to close a deal under new owner Todd Boehle, but they are working on deals for Manchester City winger Raheem Sterling and Juventus defender Matthijs de Ligt.
Chelsea were interested in De Jong when he was at Ajax in 2019 and Tuchel is said to be a huge fan.
It remains to be seen if they make a move this summer, but the process will be much cheaper than taking Declan Rice out of West Ham United.
Key players Jorginho and N’Golo Kante’s contract expires next summer, while Saul Niguez has returned to Atletico Madrid after a disappointing loan spell.
Chelsea are likely to bolster in defense after Antonio Rudiger and Andreas Christensen opted to let their contracts expire.
The 22-year-old was due to join Lyon and agreed terms with Ligue 1 last month.
However, United made a higher bid earlier this week and included a sale clause that affected Feyenoord.
Malacia could get his fix this weekend and announce it next week.
United are determined to turn their attention to Ajax defender Lisandro Martinez, according to him the athleteThey got ahead of Arsenal in the race to sign him.
Martinez is said to be keen on a reunion with former coach Ten Hag, who brought the Argentina international to Ajax in 2019.
Christian Eriksen remains a target too, as the midfielder is currently a free agent after seeing his short-term contract with Brentford expire.