At 19 years old, he has played in a World Cup as part of a talented Belgian squad. He has been the best player on the pitch more than once in his appearances for Manchester United.
There have been games where he has been less sparkling, but given his age that is no surprise.
Now, as a reward for his early promise, he has been given a squad number with a very significant legacy. When Ryan Giggs retired, there were those who suggested United should retire the number 11 shirt along with him. However, Giggs did not want the club to mark his departure in that fashion.
When asked by MUTV (h/t ManUtd.com) whether it would be appropriate, Giggs replied:
No. There are obviously special cases but it just depends on the club really. I don't think it's [right] for United where they constantly churn over great players.
There are those who would argue that a new shirt number should not exert any special pressure on a player. After all, what does it really mean, in the end?
But to deny that there is any significance to an association between a player and a number in football is to underestimate how much human beings value symbols, and seek meaning in things other than the purely rational.
The significance of a player's number has, of course, increased greatly in the era of squad numbers. A name goes above the number now, deepening the link. Players use their squad number in their twitter handles, and put it on caps and sell them. (Here is to hoping "1anuza1" does not become a thing.)
Antonio Valencia went back to the No. 25 shirt after spending a season with a number associated with several past United greats. The No. 7 shirt has been worn by club legends like Eric Cantona, David Beckham, Cristiano Ronaldo and the most amazing of them all, Michael Owen.
Valencia said, per David Maddock of the Daily Mirror "There is no negative reason as to why I changed. I don’t want people to think I wasn’t doing my job for the team because of any added pressure of wearing the No.7 shirt."
However, it was hard to shake the suspicion that a lower-profile number was appealing to Valencia as he sought to rebuild his confidence after a difficult season wearing 7.
It is hard to imagine Januzaj doing the same. He is clearly a confident young man. Back in February, speaking to the club's website, he said "I have played games and I think there is more to come. I hope to win trophies at this club and be the best player."
That kind of ambition in a 19-year-old requires a healthy degree of self-confidence. If you really do want to be the best player at a club, why not step into the shirt number of a man who is undoubtedly one of its true greats?
Especially when said great is still around to help with your development. United's former number 11 is, of course on the coaching staff. This means that if Januzaj does need advice and guidance on how to fill the shirt, he can go to the man who has worn it—or indeed any number—more than anyone else in United's history.
But, the likelihood is, if his early career is anything to go by, it simply will not be an issue. Januzaj was more than able to show his more senior colleagues what a United player is actually supposed to look like last season. His displays were often game-changing.
There is also the fact that no one expects him to live up to the exact legacy of Ryan Giggs, a man Sir Alex Ferguson described as "a unique freak." It is unreasonable to expect Januzaj to end up breaking Giggs' appearance record, for example.
He can, however, most definitely replicate the feeling of watching a young Giggs with the ball at his feet, terrifying defenders.
United's new No. 11 might be young, but he is very good indeed, and he is very confident. He is clearly ready for the step up in status associated with his designation. Like the song says, age ain't nothing but a number.