Three Miami Dolphins players on Sunday took a knee during the national anthem ahead of their game against the New England Patriots in Foxborough, Mass.

Julius Thomas, Michael Thomas, and Kenny Stills stood and applauded the Patriots' tribute to military veterans as part of the NFL's Salute to Service month, but knelt when country singer Trace Adkins took the stage for a rendition of "The Star-Spangled Banner."

Defensive back Michael Thomas and wide receiver Stills have refused to stand for the anthem since the beginning of the 2016 season, according to the Palm Beach Post.

Tight end Julius Thomas joined the protest against police brutality and other forms racial inequality in September after President Trump called players who knelt "sons of bitches," per the Post.

No Patriots players took part in the demonstration.

Earlier, New York Giants defensive end Oliver Vernon took a knee during the anthem prior to his Thanksgiving Day game against the Washington Redskins.