Eminem takes a knee during Super Bowl half-time show

Blink and you would have missed it.

But the key moment in the Super Bowl half-time show this year, which fell on Valentine's Day in Australia, was when rapper Eminem took a knee.

It's a gesture with deep symbolic significance.

San Francisco 49ers quarterback, Colin Kaepernick, took a knee.

And his career never recovered.

Kaepernick was the most high-profile player to begin kneeling during the national anthem before NFL games to protest racial injustice and police brutality against African Americans.

He began his protest in the 2016 NFL preseason.

«I am not going to stand up to show pride in a flag for a country that oppresses black people and people of colour.

»To me, this is bigger than football," Kaepernick said at the time.

When Eminem took a knee at the Super Bowl half-time show, you could be forgiven if your eyes were on music mogul Dr. Dre as he sat down at a piano and began to play.

The half-time show was a first for the NFL in its showcase of hip-hop's elites.

Dr. Dre, Snoop Dogg, Kendrick Lamar, and queen of hip-hop soul, Mary J. Blige performed, with special guests 50 Cent and Anderson .Paak.

But it was Eminem's political statement that will no doubt be the talking point in the days to come.