Donald Trump has publicly criticised American football players in recent months over the decision of some to take a knee during the national anthem before matches.

Colin Kaepernick started the act in 2016 to try and highlight racial injustice and police brutality.

Some NFL owners reportedly believe players could soon be kept in locker rooms during the anthem as a result.

And Trump has responded to the speculation on Twitter.

“The NFL is now thinking about a new idea - keeping teams in the Locker Room during the National Anthem next season,” he said. 

“That’s almost as bad as kneeling! When will the highly paid Commissioner finally get tough and smart? This issue is killing your league!…..”

Teams and even some owners have taken a knee or stood arm-in-arm after Trump in ​September said players should be fired for protesting during the playing of ‘The Star-Spangled Banner.’

“​Get that son of a b***h off the field right now, he’s fired. He’s fired​!” Trump said in an Alabama speech.

Although the size of the protests has dwindled since then, a few players are still refusing to stand.

However, Trump also accused Marshawn Lynch of “great disrespect” during Oakland Raiders’ 33-8 defeat to New England Patriots, which was being played in Mexico City at the weekend.

Trump was scathing in his denouncement of Lynch’s decision to sit during the US national anthem.

Trump tweeted: “Marshawn Lynch of the NFL’s Oakland Raiders stands for the Mexican Anthem and sits down to boos for our National Anthem. Great disrespect! Next time NFL should suspend him for remainder of season. Attendance and ratings way down.”