Eagled-eyed viewers believe they spotted some England players singing 'God Save The Queen', despite the national anthem now being 'God Save The King'.
The FIFA men's World Cup kicked off in Qatar on Sunday, with the USA and England playing their first games on Monday. The US drew 1-1 in a hotly contested affair with Wales, whilst England blew Iran away in a thrilling game that ended 6-2.
Before each game, the national anthems of both the competing countries are played and players often sing their country's lyrics with gusto.
With the passing of Queen Elizabeth II on September 8, her eldest son immediately ascended to the throne to become King Charles III, and with this, England's national anthem changed from 'God Save The Queen' to 'God Save The King'.
However, it would appear as if some of the England players reverted to habit and accidentally sang the old lyrics before their opening match against Iran, as reported by the Mirror.
Stars such as Chelsea's Mason Mount, 23, and Manchester United's Luke Shaw, 27, were the unfortunate players who viewers believe were belting out the wrong lyrics.
Viewers quickly took to Twitter to point out the error, with one person saying: "LOOOL MASON MOUNT WAS SINGING GOD SAVE THE QUEEN DURING THE NATIONAL ANTHEM".
Another said: "The FA - 'Remember boys it’s god save the king' Mason Mount - 'God save the Queen'," with a third adding: "Luke Shaw sings God Save the Queen."
This is the first time the anthem has been 'God Save The King' at a World Cup since the tournament in Brazil in 1950, so the players could be forgiven for their errors.
The history of the English national anthem stems back to the 1700s, per Royal UK: "God Save The King was a patriotic song first publicly performed in London in 1745, which came to be known as the National Anthem at the beginning of the nineteenth century.
"The words used today are those sung in 1745, substituting 'Queen' for 'King' where appropriate. On official occasions, only the first verse is usually sung."
Nevertheless, despite the apparent blunder, the team went on to win 6-2 in their opening game.
England will be fancying their chances when it comes to the World Cup, and they face off against the USA on Friday.
Let's hope the players use this week to brush up on the national anthem lyrics.