CLEVELAND, Ohio -- Even in Pittsburgh, you'd probably be hard pressed to find a lot of people wearing Alejandro Villanueva's jersey before today.

Not anymore.

The Pittsburgh Steelers offensive lineman's jersey is currently the top-selling jersey on the NFL's online store. Villanueva made headlines and gained new fans Sunday when he was the only player on his team to come out on the field and stand during the national anthem.

The rest of the Steelers opted to stay in the tunnel as a show of unity following President Trump's comments over the weekend criticizing NFL players.

While Villanueva's jersey shot up on the sales chart overnight, his apparent act of defiance got an icy reception from his head coach Mike Tomlin.

"I was looking for 100 percent participation, we were gonna be respectful of our football team," Tomlin told reporters after the team's loss to Chicago.

But on Monday, Villanueva sought to clarify what happened, telling reporters he didn't mean to stand alone, but got separated from the rest of his teammates who were standing under the tunnel when the anthem started.

"Every single time I see that picture of me standing by myself, I feel embarassed," Villanueva said according to the Pittsburgh Post-Gazette.

"I made coach Tomlin look bad, and that is my fault and my fault only," he said. "I made my teammates look bad, and that is my fault and my fault only.

"When everybody sees an image of me standing by myself, everybody thinks that the team and Steelers are not behind me, and that's absolutely wrong. It's quite the opposite. Actually, the entire team would've been out there with me, even the ones that wanted to take a knee."

Villanueva is a former U.S. Army Ranger who served three tours in Afghanistan. While it's rare for an offensive lineman to have the top-selling jersey, his No. 78 jersey is currently outselling the likes of superstars Tom Brady, Aaron Rodgers and Marshawn Lynch.