That is the view of United first-team coach Phil Neville, who believes it is vital for teenager Januzaj to be given time to develop into a top-class player.
The emergence of the 19-year-old has been one of the few positive points of a below-par season for United, with the reigning Premier League champions sitting sixth in the table and facing a 2-0 deficit ahead of the second leg of their UEFA Champions League last-16 tie with Olympiacos.
Belgian-born Januzaj, who joined United from Anderlecht in 2011, has made 26 appearances in all competitions this term, scoring three goals, and put pen to paper on a new five-year contract in October.
However, while praising the impact Januzaj has had in his fledgling Old Trafford career, Neville feels the playmaker is far from the finished article and should not be expected to play every game while he adapts to the demands of performing at the highest level.
"Everyone knew we had a special talent on our hands, but the real test comes when you play at Old Trafford," Neville told United's official website.
"So that was the question back in pre-season: has he got the temperament to play for Manchester United at Old Trafford?
"Well, I think he's answered that. You have to have the courage, the belief, the confidence, the determination to play for Manchester United - those characteristics are key to a player's success here and Adnan is no different.
"It's still early doors for him, though, and I think we've treated him right. We've played him in games and we've also rested him in others and given him a bit of a breather.
"We have to make sure that in two or three years he's still improving and reaching the levels we hope he can reach. That's our job as coaches."
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