The Belgian rose to prominence during his time under David Moyes at Old Trafford, but struggled to build on that during his time with Borussia Dortmund last season.
After not picking up chances to impress at Man United, Januzaj went on loan to Premier League rivals Sunderland for the 2016/17 campaign.
Speaking about his situation, Januzaj has opened up about his relationship with Mourinho.
“I never had any problems with [Jose] Mourinho. He is a top coach. Last summer, they asked me to play a year on loan, to get some game-time because I had not played for a year,” he said.
“I joined Sunderland for playing time and to continue to make progress. After this season we’ll see again.
“I’ve always had confidence in my football qualities. I’ve never been afraid of anything.”
He’s made 14 top flight appearances for the Black Cats this term and has a long way to go before he can think about slotting back into the starting XI at Old Trafford.
Januzaj needs to re-find his best form under Moyes if he has a chance of genuinely returning to Old Trafford and playing a vital role under Mourinho.