Manchester United midfielder Adnan Januzaj is reportedly refusing to change with the club's reserve team after being told by manager Jose Mourinho he does not feature in his plans. The 21-year-old Belgian has slipped down the United pecking order since bursting on the scene in 2013 and it appears increasingly likely that his long-term future lies away from Old Trafford.

Januzaj is said to be angry he has not been included in Mourinho's 26-man squad for the new season, and has responded to the setback by refusing to change with the club's reserve players. On one occasion, he changed for training in a toilet adjacent to the under-21 dressing room, according to The Mirror, which said that the youngster has also taken to arriving at training wearing his kit.

"Januzaj is furious that he's not part of Mourinho's squad and has basically been banished to change in the Under-21 dressing room," a United source told The Sunday Mirror. "He has spent the last couple of seasons with the first team when he's not been out on loan and feels he should have been treated better."

The talented winger apparently feels he has been treated in a disrespectful manner by the new United boss, who has previously stated his wish to work with a squad of 26 players, including three goalkeepers. The decision has also led to the exclusion of World Cup-winning midfielder Bastian Schweinsteiger, who signed for United in 2015.

Mourinho recently admitted he does not see Schweinsteiger as part of his long-term vision for United. "It happens at every club in the world. The manager decides his squad," Mourinho said recently. "I choose a certain number of players to face the season, that is it. I like to work with 20 and three keepers - I have done it for 15 years.

"We have so many players but so many competitions and the Europa League changes a lot. We could play 15 matches in it, on Thursdays, and there is normally Premier League on Sundays. I have made a decision to have 23 and 3. It is still a lot. I had to make my decisions."

Meanwhile, former United boss David Moyes recently revealed he was keen to sign Januzaj for Sunderland. The newly appointed Mackems manager said he was interested in the Belgian and his teammate for club and country, Marouane Fellaini.

"We're interested but I'm sure there's a load of other clubs that are as well. We're interested in lots of good players," Moyes said. "You have to have a realistic view. There'll be some players we can attract just now and some players we can't."