Another young United forward, Adnan Januzaj, enjoyed a strong breakthrough season at the club before his career stalled and questions started to be asked about his attitude. Januzaj is on loan at Sunderland after a calamitous loan spell at Borussia Dortmund was cut short last term.
Van Gaal had suggested previously that Martial wanted to play more centrally and it is thought the Frenchman was unhappy about Zlatan Ibrahimovic taking the No 9 shirt off him in the summer. Martial now wears No 11.
Martial has scored 18 goals in 58 appearances for United so far. Under the terms of the contract he signed in September last year, United – who paid an initial £36.3 m for the player – will have to pay Monaco an additional €10 m (£8.75 m) once he reaches 25 competitive goals for the club.
There will also be an additional £8.75 m payment if he plays 25 matches for France. He has currently made 14 appearances for his country, although only matches in which he plays for at least 45 minutes count as an appearance. Another £8.75 m payment is due to Monaco if Martial is nominated for the Ballon d’Or.
United midfielder Ander Herrera has been called up to Spain’s senior squad for the first time in his career. The 27-year-old has been included in Julen Lopetegui’s squad for the World Cup qualifying matches against Italy tomorrow and Albania on Sunday after injury forced Bayern Munich’s Javi Martínez to withdraw.