Manchester United manager Jose Mourinho has questioned Andreas Pereira's decision to leave the club on loan, suggesting the player is "not ready to fight for something difficult".

Pereira, 21, was included in United's pre-season tour squad in the summer before taking number 15 in the first-team ahead of the new Premier League campaign, suggesting he was very much part of the manager's plans for the 2017-18 campaign.

But on the final day of the Spanish transfer window, the midfielder returned to Spain to join Valencia on a season-long loan, having enjoyed an impressive campaign in the Spanish top flight with Granada last season.

Pereira, a Belgian-born Brazil youth international, signed a contract extension until 2019 prior to his move to the Mestalla with United exercising an option to extend it by a further year.

But speaking at a press conference ahead of United's Premier League clash with Stoke City on Saturday, Mourinho explained he was disappointed with the player's decision not to stay and fight for a starting berth.

"Andreas Pereira was a personal decision, a decision that I don't agree with, a decision I don't honestly think is the best decision for him, a decision that disappoints me a little because I think he has the potential to be fighting for opportunities and to be a Manchester United player," Mourinho said.

"His decision can be considered as a young player who wants to play every weekend, but can also be considered as one for a player that is not ready to fight for something difficult, and it is difficult to play in Manchester United's midfield."

While clearly unable to hide his disappointment with Pereira's decision, Mourinho revealed the club do have the option to recall the player in January.

"You have to be ready to fight for the position and I am a bit disappointed he left. But it was his decision. I open the door for his decision. He has a long-term contract. We have the option to bring him back on 1 January. We have the situation under control. It is not a drama but it is a decision that disappoints me."

Andreas Pereira
Pereira's decision to push for a loan move disappointed his manager. Getty