The Pittsburgh Steelers “butchered” their attempt at unity by sitting out the national anthem Sunday, the lone player to appear for the anthem said on Monday.

“This national-anthem ordeal has been out of control, and there’s a lot of blame on myself,” lineman Alejandro Villanueva said Monday.

“Obviously, we butchered it. Unfortunately, I threw [my teammates] under the bus, unintentionally.”

The squad opted to stay in their locker room in Chicago rather than risk appearing divided if some players joined a league-wide movement to kneel during “The Star-Spangled Banner.”

Villanueva, a former Army Ranger, was allowed to poke his head out of the tunnel leading to the locker room just far enough to see Old Glory.

He apparently came out too far, and a photo of the veteran standing hand-over-heart went viral.

“Every single time I see that picture of me standing by myself, I feel embarrassed,” he said.

But once “The Star-Spangled Banner” began playing, it “would have looked extremely bad” to go back into the tunnel, he said.

Sales of Villanueva’s jersey skyrocketed overnight and it was the league’s No. 1 seller Monday.

Earlier in the day, Steelers quarterback Ben Roethlisberger revealed he was “unable to sleep” Sunday night because he regretted sitting out the anthem.

“The idea was to be unified as a team when so much attention is paid to things dividing our country, but I wish we approached it differently,” he said.

The team will assemble on the sidelines for anthems in the future, Roethlisberger said. “What we do when we’re out there has yet to be determined,” he added.