Star's jersey sales soar amid anthem protest controversy

San Francisco 49ers quarterback Colin Kaepernick greets fans after the 49ers' 31-21 win over the San Diego Chargers during an NFL preseason game last week in San Diego. Photo / AP

Colin Kaepernick's high-profile protests appear to have reinvigorated the market for his US football jersey.

On Monday, the backup quarterback's No. 7 jersey was the best seller among current 49ers players in the team's online store, jumping from the No. 6 spot, according to Marketwatch.

Leaguewide, the jersey is now the third most popular in the NFL's online store, jumping 17 places from where it ranked just over a week ago, ESPN reported. Only Dallas Cowboys running back Ezekiel Elliott and New York Giants wide receiver Odell Beckham's jerseys outsold Kaepernick's.

Kaepernick, an active supporter of the #BlackLivesMatter movement, became a household name even among non-football fans late last month when he was spotted sitting while the national anthem played ahead of a preseason game against the Green Bay Packers.

"I am not going to stand up to show pride in a flag for a country that oppresses black people and people of colour," Kaepernick said when asked about it after the game. "There are bodies in the street and people getting paid leave and getting away with murder."

Referring to police killings of mostly unarmed black men, Kaepernick's actions angered some members of the Santa Clara, California, police union, who threatened to stop securing Levi's Stadium as long as Kaepernick's actions remained acceptable to the team. (The 49ers have remained neutral.)

Other groups, however, have lauded Kaepernick for putting social issues above football, including his team-mate safety Eric Reid, who knelled during the anthem with Kaepernick on Friday, and soccer standout Megan Rapinoe, who knelled during the anthem on Monday ahead of a game between the Seattle Reign and the Chicago Red Stars.

"We need a more substantive conversation around race relations and the way people of colour are treated," she said after the game.

Even US President Barack Obama has got involved. He told journalists while travelling in China that Kaepernick is "exercising his constitutional right" to sit during the national anthem, while conceding that the protest could be a "tough thing" for military service members to accept.

Kaepernick's actions have offended some military members, but certainly not all. Enough veterans have expressed their support for the quarterback that the hashtag #VeteransforKaepernick trended worldwide on social media late last month.

Kaepernick has promised to donate US$1 million of his earnings to charities that support racial equality.

"I've been very blessed to be in this position and make the kind of money I do," the player, who will make a base salary of US$11.9 million this season with the 49ers, said last week. "I have to help these people.