Martial only has a contract at Old Trafford until next June, and the Red Devils allegedly have no desire to activate a 12-month extension in his deal.
As a result, the France international will seemingly leave Old Trafford on a free transfer at the end of the campaign unless he secures a mid-season exit.
The 28-year-old has been a regular for Man United during the 2023-24 campaign, featuring on 19 occasions in all competitions, but he has only scored two goals and registered two assists.
Martial has one Premier League goal to his name in 2023-24, but he was given a start against Bournemouth in England's top flight last weekend, featuring for 56 minutes of his side's 3-0 loss.
The forward did not play against Bayern Munich in the Champions League on Tuesday, though, as he was unavailable for selection due to illness.
Martial is expected to be back in the squad against Liverpool on Sunday afternoon, but it would be a shock to see him start despite Rasmus Hojlund's goal problems in the Premier League.
There is currently a host of speculation surrounding Martial's future, with various clubs in Saudi Arabia said to be closely monitoring developments.
According to journalist Ekrem Konur, Al Ettifaq are lining up a €10m (£8.6m) offer for the former Monaco youngster, who has 90 goals and 55 assists in 317 appearances for Man United in all competitions.
Al Ettifaq were linked with a move for Jadon Sancho in the latter stages of the Saudi Arabian summer transfer window but are thought to have dropped their interest due to the cost.
Steven Gerrard's side currently have Moussa Dembele leading their line, with the Frenchman scoring nine times in 10 appearances during the 2023-24 campaign.
Ex-Liverpool midfielder Georginio Wijnaldum, meanwhile, is the second-highest goalscorer in their squad with six goals.
Martial's Man United teammates Casemiro and Raphael Varane are also being linked with moves to Saudi Arabia, with the Red Devils thought to be willing to let the former Real Madrid duo depart.
Sancho and Donny van de Beek are also set to leave during the January transfer window, which would open up space for Erik ten Hag's side to make a couple of mid-season additions.