Trump (figuratively) kicking off the game, was heard yelling an anti-Trump slur before taking the field.
Footage showed Trump mouthing the wrong words as a choir of four harmonised, "at the twilight's last gleaming", and during other segments of The Star-Spangled Banner.
On Twitter, June Yoon said: "Our national embarrassment doesn't know our national anthem".
It's also worth pointing out that Trump tweeted about the importance of the national anthem earlier today, saying that he wants our flag respected and "we want our NATIONAL ANTHEM respected also!"
ZBB wasn't alone in the center of the field as President Trump, accompanied by men and women of the armed forces, stood nearby at attention for the historic moment. The general fear is that he is developing Dementia and Twitter users in America have not stopped coming for him for seemingly forgetting the words to the American national anthem.
Previous surveys have found that many American's don't know the full lyrics to the United States anthem, but for the United States president, a man who has attacked footballers for their actions during the anthem, his inability to sing the lyrics proved unpopular online.
He added to applause: "We want our national anthem respected, too". People who oppose President Trump were obviously quick to point out the error, but after a while, even his supporters began sadly noting that he looked out of sorts.