After initially being registered for the UEFA Youth League, the promising forward was added to the senior squad once he became eligible to feature on the club's B list of players. It led to Januzaj being an unused substitute against Real Sociedad at Old Trafford and he will remain in the manager's plans for the trip to San Sebastian.
"He's definitely ready to play [in the Champions League]," asserted Moyes. "He's not got a problem. We're trying to bring the boy along at the right pace if we can. He's not tired and we've not seen any dips in form just now so I'm sure we'll continue using him and he'll definitely be in and around the squad."
There has been plenty of discussion of late about Januzaj's best position but the boss is happy to ensure he can make a positive contribution drifting off the flanks, as opposed to performing in the more central role he occupied against Norwich City last week and in the second half against Fulham.
"In time, his best position may be no.10 but, while he's so young, it's easy to introduce him off the left or off the right," added Moyes. "He's that talented, he can play in several positions and I'm in no hurry to play him as a no.10. I want to keep the reins on him a little bit and keep him disciplined in what he does.
"The boy is working really well and whatever job we give him he's a real talent. I don't want to put too much expectation on the boy, which is why I'll undoubtedly take him out of the team at times during the year so he doesn't get too much [exposure]. But he's got something I've not seen for a long, long time in [terms of] what he can do."