The jersey for an obscure NFL player and veteran shot to the top of the bestseller charts after he went against the rest of his team and stood out, hand on his heart, during the national anthem.

Army veteran and lineman Alejandro Villanueva, 29, took a tongue lashing from Pittsburgh Steelers head coach Mike Tomlin, after taking part in the pre-game national anthem ceremony on Sunday while the rest of his team remained out of sight in the locker room.

However on Monday he admitted it was a mistake saying: 'Unfortunately I threw my teammates under the bus, unintentionally.

'Every single time I see that picture of me standing by myself I feel embarrassed.'

Villanueva explained that he had asked to stand in the front of the team with the captains of the squad but did not stop as they walked to the opening of the tunnel, ending up in plain view on the field as the national anthem began to play.

He also lashed out at those who have attacked the team's coach, Mike Tomlin, for allowing the boycott.

'For anybody who thinks Coach Tomlin is not as patriotic as you can get in America, I’m offended by that,' said the Army veteran.

Pittsburgh Steelers head coach Mike Tomlin was not happy with his player Alejandro Villanueva's (pictured) decision to take part in the pre-game national anthem ceremony on Sunday

Villanueva stood at the tunnel opening at Chicago's Soldier Field with his hand over his heart as the Star Spangled Banner was performed despite Tomlin (pictured Sunday) asking the team for '100 per cent participation'

Villanueva, who was an Army Ranger (left) and served in Afghanistan, was the only player on the active squad that could be seen by the crowd

Following his team's 23-17 loss to the Chicago Bears Tomlin said: 'Like I said, I was looking for 100 per cent participation, we were gonna be respectful of our football team.'

Villanueva, who served three tours in Afghanistan as an Army Ranger, stood at the edge of the end zone at Chicago's Soldier Field with his hand over his heart as the Star Spangled Banner was performed.

His teammates, who were surprised by Villanueva's actions, remained either in the locker room or stood near the tunnel out of sight of the crowd.

The remainder of the team was either in the locker room or standing near the tunnel out of sight of the crowd

Villanueva also said that he has no issue with his teammates or anyone else in the league taking a knee during the national anthem.

'I will support all my teammates, and all my teammates and all my coaches have always supported me,' said Villanueva

Tomlin, offensive coordinator Todd Haley, offensive line coach Mike Munchak and running backs coach James Saxon all stood on the field for the national anthem.

But Villanueva, who was an Army Ranger and West Point graduate, was the only player on the active squad that could be seen by the crowd.

And overnight, that decision made an impressive impact on the athlete's jersey sales as fans rallied to his side by way of the NFL marketplace.

Villanueva jerseys were the No. 1 seller in the men's and women's categories on both Fanatics.com and NFLshop.com. It's the No. 2 youth jersey on both sites.

The lineman's jersey sales mirror that of Colin Kaepernick, whose jersey became the No. 1 seller for the San Francisco 49ers after his protests against the anthem began in 2016.

After the game, Tomlin said that many of the players 'felt like something needed to be done'.

'I asked those guys to discuss it and whatever they discussed that we have 100 per cent participation or we do nothing,' Tomlin said.

Before the game, Tomlin had told CBS Sports that the team would not stand on the sidelines for the anthem as they usually did.

He said the team held a meeting and decided not to come out of the locker room for the anthem.

Tomlin noted the decision wasn't unanimous, but the intent was to have his team focus on the game and not President Donald Trump's comments about players who chose to protest during the anthem.

'We're not going to play politics,' Tomlin said. 'We're football players, we're football coaches. We're not participating in the anthem today - not to be disrespectful to the anthem, but to remove ourselves from the circumstance.'

He added: 'People shouldn't have to choose. If a guy wants to go about his normal business and participate in the anthem, he shouldn't be forced to choose sides.

'If a guy feels the need to do something, he shouldn't be separated from his teammate who chooses not to. But when we come out of locker rooms, we come out of locker rooms to play football games.'

Villanueva was a key member of the team's protest planning ahead of Sunday's game, a source told ESPN.

'Like I said, I was looking for 100 per cent participation, we were gonna be respectful of our football team,' Tomlin (pictured) said following his team's 23-17 loss to the Chicago Bears

Before the game, Tomlin said the team would not stand on the sidelines for the anthem as they usually did. He said the team held a meeting and decided not to come out of the locker room for the anthem

Head coach Mike Tomlin, offensive coordinator Todd Haley, offensive line coach Mike Munchak and running backs coach James Saxon all stood on the field for the national anthem

The Pittsburgh Steelers side of the field was nearly empty during the playing of the national anthem before a game between the Steelers and Chicago Bear

Players wanted to accommodate Villanueva, who expressed that he didn't want to be singled out for wanting to stand during the anthem.

The team decided that moving the protest off the field and out of sight of the crowd was a way to keep solidarity - those who wanted to stand could still stand inside the tunnel.

Linebacker James Harrison told Penn Live that everyone was involved in the pregame plan to remain out of sight of the crowd.

'We thought we were all in attention with the same agreement, obviously,' Harrison said. 'But I guess we weren't.'

Villanueva has previously said he supported players' frustration over racial injustice, but he didn't want to overlook the anthem because of his time in the military, where he earned a bronze star for valor during his tours overseas.

Several people took to social media to praise Villanueva for his decision to stand near the field during the pregame national anthem, including Lara Trump.

'Kudos to this incredible American. Thank you for your service & respecting our flag, sir. (sic) (Only #Steeler to come out for nat'l anthem),' the president's daughter-in-law tweeted.

Others called the Steelers a 'disgrace' for not taking part with Villanueva, despite their move to stay out of sight to remain out of the protest narrative.

Teammates said on Sunday that they respected Villanueva's decision.

Several people took to social media to praise Villanueva for his decision to stand near the field during the pregame national anthem, including Lara Trump

'Al is a unique circumstance, what he's been through, some of the things he's talked about before,' guard David DeCastro said. 'I've got a lot of respect for Al.

'I wish there was a different way to do this thing. We've got some people who look at the national anthem as patriotism, soldiers, all the stuff that it means, and obviously, people are upset, and I understand that.

'I just wish both sides understand that they want the right thing, but doing it through the national anthem, I wish there was a different way.'

Defensive end Cam Heyward said: 'I don't want to go into that, but we support our guy Al. He feels he had to do it. This guy served our country, and we thank him for it.'

Villanueva' s entire family is from Spain, but he was born in Mississippi while his father, Ignacio Villanueva, was stationed there as part of the Spanish Navy.

When Alejandro Villanueva was 15 years old, he attended a US Military-funded high school in Casteau, Belgium.

The football star officially married his wife Madelyn (pictured) in 2013 at small ceremony, but in 2015, the couple had a much larger wedding.

Villanueva later graduated from West Point, where he also played football. He was immediately in charge of a 38-person unit upon arriving in Afghanistan because of his West Point experience

During his first tour in 2011, Villanueva (center) had his worst experience in Afghanistan. He was leading his men on a mission when they were ambushed, and one of his soldiers were killed

Villanueva (second from left) was awarded the Bronze Star for his efforts. He then joined the Army Rangers and went back to Afghanistan in 2012 and 2013

Villanueva later graduated from West Point, where he also played football.

He was immediately in charge of a 38-person unit upon arriving in Afghanistan because of his West Point experience.

During his first tour in 2011, Villanueva had his worst experience in Afghanistan. He was leading his men on a mission when they were ambushed, and one of his soldiers were killed.

Villanueva was awarded the Bronze Star for his efforts.

He then joined the Army Rangers and went back to Afghanistan in 2012 and 2013.

The football star officially married his wife Madelyn in 2013 at small ceremony, but in 2015, the couple had a much larger wedding.

In 2014, Villanueva, then a member of the Philadelphia Eagles, told CBS News why he joined the Army.

'I just couldn't stand by the sidelines and watch other people do the work,' he said.

In 2014, Villanueva, then a member of the Philadelphia Eagles, told CBS News why he joined the Army. 'I just couldn't stand by the sidelines and watch other people do the work,' he said

Meanwhile, the Chicago Bears stood together with linked arms as the national anthem played at Soldier Field on Sunday

More than 200 NFL players who either knelt, sat, stretched or prayed during the Star Spangled Banner to protest Trump's remarks on Sunday.

Three teams didn't even take the field until the national anthem was over.

Several players raised their fists during the protest, while others did so after scoring touchdowns during the game.

The protest campaign against racial inequality was started last year by former 49ers quarterback Kaepernick. Only six players participated last week.

But Trump's weekend attack on athletes sparked angry reactions from around the sports world and drew defiance from most of the NFL.

He suggested the NFL was going soft for cracking down on big hits. He uninvited the NBA champions Golden State Warriors to the White House after Stephen Curry and other players indicated they weren't sure they would accept the invitation.

Players, owners and commissioners past and present chastised the president for his divisive remarks.

After calling for NFL players who protest to be fired, Trump tweeted Sunday that the league should make it mandatory to stand for the national anthem and that fans should shun anyone who doesn't.