J.J. Watt could not "fully understand" the boos heard during a pre-game moment of unity in protest against racism and social injustice ahead of the NFL's season opener.
Players from Super Bowl champions the Kansas City Chiefs and the Houston Texans linked arms prior to Thursday's contest, which the Chiefs won 34-20 at Arrowhead Stadium.
The Chiefs are among the teams letting supporters into their arena during the coronavirus pandemic and, despite fewer than a quarter of the seats being filled, boos could be heard from pockets of the stands.
"The moment of unity I personally thought was good," Texans defensive end Watt told NFL Media.
"I mean the booing during that moment was unfortunate. I don't fully understand that. There was no flag involved. There was nothing involved other than two teams coming together to show unity."
The NFL has opted to alter its stance on protests this season, with end zones to bear the words "End Racism" and "It Takes All of Us", while players can display the names of victims of social injustice on their safety helmets.
Houston players stayed in the locker room during the national anthem, while the Chiefs' Alex Okafor took a knee.
Chiefs tight end Travis Kelce said: "[We wanted to] let everyone know that we had their back.
"You can go ahead and whatever you feel is the right decision in your heart, you have your brother's back and you have your brother's support on this team.
"And we made sure that everybody was comfortable in that area and they weren't gonna get backlash from anybody on this team for doing that.
"And I thought it was a great show of unity amongst both of us, the Chiefs and the Texans.''
Texans coach Bill O'Brien stated he did not hear any booing and pondered whether the jeers may have actually been for his team as the opposing side.
"I thought that that was a nice thing to do, so I'm not sure why they would boo that," O'Brien said.
"Maybe they were just booing us because we had just come on the field as the visiting team. But yeah, I thought that that was a nice gesture."
Chiefs coach Andy Reid also said he did not hear the boos and added: "I thought that was kind of a neat deal, both sides coming together for a cause and the story was told there.
"We can all learn from this, and really it's just to make us all better, even a stronger country than we already are. We have a chance to just be completely unstoppable when all hands join together and that's a beautiful thing."