Immediately after the 3-1 win, the boss told MUTV there was no need for the 18-year-old to receive extra protection because he was learning that the best way to respond to any fouling was to get to his feet and retaliate with his trickery on the ball.
However, it is clear that the Fulham full-back overstepped the mark towards the end of the game at the weekend, which understandably led to some frustration on Januzaj's part.
The Football Association have since confirmed that Riether has been charged with violent conduct and has until 6pm GMT on Tuesday to respond to the charge.
"I hadn't seen it until after the game," the manager explained. "The distance we were away made it impossible to take it in. It's a bad stamp and it does look deliberate. But that's for the referee to deal with on the day or, if nowadays they look at it differently, they can decide afterwards.
"I do think Adnan may need a bit of protection. He's getting kicked so I think he deserves a bit more protection than what he's getting at this present moment in time."
Moyes feels Januzaj has the perfect role model in this respect in Barcelona star Lionel Messi, who has taken knocks throughout his career but, despite his small frame, rides the challenges and is quick to bounce to his feet.