"I was pretty upset when they weren't showing respect to America during the national anthem," Shockey said. "There were about 10 players who didn't put their arms across their chest. This is America. They should at least give respect to America."
The Panthers went on to win their game against the Texans 28-13.
When Texans linebacker DeMeco Ryans heard of Shockey's comments, he turned the table on him, the Houston Chronicle reported Sunday.
"If he's so patriotic, why was he looking at our bench instead of the flag?" Ryans said. "Where did he come up with the number 10? Was he counting? Why was he paying attention to us during the national anthem?"
Shockey turned up his patriotism Sunday night via Twitter.
"GOD bless America" was his first tweet from Sunday after the game.
Shockey later wrote, "My words were not to offend Anyone, football is just a sport and America is home."
"Stand tall and proud," he continued on Twitter. "It's our duty as citizens to pay tribute to the ones that gave us our freedom."
Ryans said the Texans do.
"Of course, our players are patriotic," he said. "We respect the flag and America and our soldiers that are fighting for our freedom."