The majority of Houston Texans players knelt during the national anthem prior to Sunday's NFL game against Seattle Seahawks to protest against comments made by team owner Bob McNair.
Several Seahawks players also sat during the anthem to show support for the Texans.
McNair, who has said he wants his players to stand during the anthem, mangled a figure of speech earlier this month by referring to NFL players as prison inmates, faced an immediate backlash and later issued an apology.
McNair was quoted in a lengthy ESPN article as speaking at an NFL team owners' meeting about protests during the national anthem.
"We can't have the inmates running the prison… the inmates are running the asylum," he said.
McNair issued a statement on Friday, saying he regretted using that expression.
"I never meant to offend anyone and I was not referring to our players," McNair's statement said.
"I used a figure of speech that was never intended to be taken literally. I would never characterize our players or our league that way and I apologize to anyone who was offended by it."
Texans receiver DeAndre Hopkins and rookie running back D'Onta Foreman sat out Friday's practice in response to McNair's comment.