Riether was not punished for his actions by referee Lee Probert, which came in the last minute of Fulham's 3-1 defeat at Craven Cottage.
"For me it was a red card for the right-back," the Belgian told MUTV. "I hope the referee looks at the video later."
United manager David Moyes was more philosophical after his team extended their unbeaten run.
"We are never going to ask for (protection)," said Moyes.
"We want (Januzaj) to get up. We don't want him to go down easily.
"He is a really honest boy and I thought there were a couple of times when fouls should have been given against him but they weren't."
@jd.quench - that's not what I said though, is it? I just questioned Moyes' description of him as an honest lad when he was booked for diving in his first PL start. This was a clear stamp so I totally agree with the fact Riether should be punished, but to claim that Januzaj is any more honest than your average footballer is a farce.- ray_bandana