TV presenter Willoughby, 42, was one of the ceremony's VIP attendees for years alongside former co-star Phillip Schofield, regularly sweeping up trophies and sometimes even turning up for their ITV show the next day still in their outfits from the night before.
But after Schofield, 61, quit This Morning after 21 years in May and details of his relationship with a much younger member of production staff emerged, it was unclear whether Willoughby would still be in the audience at the NTAs which take place at London's O2 on Tuesday night.
During an interview with ceremony host Joel Dommett on Monday's This Morning, Willoughby appeared to confirm that she would be at the event as usual.
Putting her arm around co-host Alison Hammond, she told Dommett: "Good luck tomorrow night, we'll see you there."
Hammond, 48, presents Friday episodes of This Morning with Dermot O'Leary and had previously been a stand-in presenter for other days, but has taken on a more prominent role since Schofield's departure.
She is shortlisted in the TV Presenter award category, which Willoughby did not make the cut for - although Ant and Dec, also shortlisted, are known for scooping the award each year.
Monday was Willoughby's first day back as host of This Morning after a longer summer break than usual, which saw a rotating line-up including Hammond, O'Leary, Josie Gibson and Rochelle Humes covering shows.
She and Hammond danced together to Abba's Dancing Queen as the show opened and Willoughby seemed to tease a revamped This Morning as she said: "What a start to the show. It's so good to see you all. We are back from our summer break.
"With a new season comes new adventures."
Hammond later informed her that the Spin To Win prize segment had made a cut - the option for viewers to choose Willoughby picking prizes from a ball machine instead of spinning a wheel has been dropped.
Willoughby asked: "What happened to my balls over the summer?"
Hammond said: "They were so dry. We got rid of your balls. It's called Spin To Win."
Spin To Win has been at the centre of its own controversy on the show after its prize to pay for viewers' energy bills was criticised as insensitive.
Willoughby last appeared on This Morning on Thursday, 6 July - quietly beginning her summer break two weeks earlier than usual.