Januzaj came off the bench to help inspire United's 3-2 comeback win over Stoke at Old Trafford on Saturday and Moyes believes his slender build belies a ferocious competitive instinct.
Januzaj is is line to start for United along with Saturday's match-winner Javier Hernandez in the Capital One Cup clash with Norwich at Old Trafford on Tuesday.
Moyes said: "If ever there was a boy who can take it, it will be him.
"You just hope the referees give him the correct protection, and I'm sure they will, but he won't be moaning about it - he's a great lad and he'll bounce up and get on with it.
"You can kick him as hard as you like and it won't affect him."
Moyes has admitted that Wilfried Zaha is in contention to face Norwich despite not yet making his Premier League bow for the champions.
Zaha has been linked with a possible loan switch away from United in January.
"I just don't think we have had the right opportunity to get him on as much as would have liked," Moyes told the United website.
"We don't want to put him in too quickly. We want to make it the right time.
"I've said I would look at it in January as I wanted to have him here for six months to see how we work. I told him we would try to get him minutes but the competition in the wide areas we have with Nani, Antonio Valencia, Ashley Young, Adnan Januzaj and even Shinji Kagawa playing off the side means we are as strong there as anywhere.
"It's not that Wilf has done anything wrong, it's just that we have big competition and we have to try to make sure he gets some playing time. Unfortunately, we haven't done that with Wilf and, if it's still the case in January, we would look at it. But he is very much in my plans and in my thoughts all the time."
United head into the clash with the Canaries keen to keep their good run going after back-to-back successes against Stoke and Real Sociedad went some way towards improving on their sluggish start to the season.
After Saturday's bruising encounter Moyes will have to check his treatment table before confirming his squad for the game.
Moyes said: "We have got a squad of first-team players who are all capable of playing and everyone is used to that, the crowd see that and expect it.
"We will see what we have got. We have one or two knocks and niggles which we will assess.
"But we are beginning to tick along, quite quietly."
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