Martial told Ralf Rangnick that he would like to leave January, but United turned down an offer from Spain because they offered only half of Martial's wages.
ESPN has been told by sources that they will not consider any offers that do not cover Martial's wages or include a loan fee.
- Ronaldo to Barca Spain's prank stories on 'Dia de los Inocentes'
- ESPN+ guide: LaLiga, Bundesliga, MLS, FA Cup, more (U.S.)
- Do you not have ESPN? Get instant access
United will keep the 26-year old if necessary.
Martial is back in full training, but was not included in the squad for Monday's 1-1 draw against Newcastle. Since the Nov. 23 win over Villarreal, Martial has been absent.
France International is currently under contract at Old Trafford through 2024. There is an option to extend the contract by one year after having signed a 2019 extension.
Since joining United from Monaco in 2015, when Louis van Gaal was the manager, he has scored 79 goals in 268 appearances.
Martial, who has had limited opportunities this season due to the arrivals of Jadon Sancho (Cristio Ronaldo) and Jadon Sancho (Premier League), has only started twice.
He was the first-choice centre forward under Ole Gunnar Solskjaer in 2019-20. He scored 23 goals, including 17 league goals. However, he told Rangnick that he is looking for a new challenge.
Rangnick stated that Rangnick explained to him that he had been with Manchester United for seven years now and feels it's time to make a change.
"I think in such a way that is understandable, I could also follow his thoughts but it's important to see the club's situation.
"We have COVID-19, three competitions in the which we still have high aspirations and we want as much success as possible."