Drew Brees has angered his team-mate Michael Thomas by saying he still does not approve of people kneeling in front of the American flag during the United States national anthem.
Colin Kaepernick began kneeling during the anthem in 2016 to protest against police brutality and racial inequality.
New Orleans Saints quarterback Brees takes offence to the gesture, which he believes is disrespectful to those in the military.
"I will never agree with anybody disrespecting the flag of the United States of America or our country," Brees said when asked about players kneeling in an interview with Yahoo Finance on Wednesday.
"Let me just tell what I see or what I feel when the national anthem is played and when I look at the flag of the United States.
"I envision my two grandfathers, who fought for this country during World War II, one in the Army and one in the Marine Corp. Both risking their lives to protect our country and to try to make our country and this world a better place. So every time I stand with my hand over my heart looking at that flag and singing the national anthem, that's what I think about."
The 41-year-old does see a connection between the sacrifices made by those in the military and those fighting for civil rights, but still feels the flag should be respected.
“In many cases, that brings me to tears, thinking about all that has been sacrificed," he said. "Not just those in the military, but for that matter, those throughout the civil rights movements of the '60s, and all that has been endured by so many people up until this point.
"And is everything right with our country right now? No, it is not. We still have a long way to go. But I think what you do by standing there and showing respect to the flag with your hand over your heart, is it shows unity. It shows that we are all in this together, we can all do better and that we are all part of the solution."
Brees' comments come a day after Blackout Tuesday, a day established to observe, mourn and bring policy change in the wake of the death of George Floyd, the African-American who died on May 25 while in the custody of police in Minneapolis, Minnesota.
Since Floyd's death, people have been protesting in several American cities, calling for an end of police brutality against minorities, and the NFL and the league’s teams are addressing ways of supporting and fighting for justice.
Shortly after Brees' interview, Thomas took to Twitter to respond to his quarterback’s opinion.
"He don't know no better." Thomas wrote in one tweet.
He followed up a few minutes later with another message directed at Brees.
Thomas added: "We don't care if you don't agree and whoever else how about that."
Brees then tried to clear the air with his team-mate and others criticising him.
"I love and respect my team-mates and I stand right there with them in regards to fighting for racial equality and justice," Brees said in a statement to ESPN. "I also stand with my grandfathers who risked their lives for this country and countless other military men and women who do it on a daily basis."