Miami Dolphins wide receivers, Kenny Stills and Albert Wilson, take a knee during the national anthem

The NFL saw its first protests related to next season's national anthem on Thursday, with two Miami Dolphins players taking one knee during the Star-Spangled Banner and three Seattle Seahawks waiting in the tunnel until it was over.

Dolphins critics Kenny Stills and Albert Wilson knelt during the anthem, while defensive end Robert Quinn mounted a separate protest by raising his right fist and shaking his head.

Meanwhile, Seahawks defensive linemen Branden Jackson and Quinton Jefferson joined offensive lineman Duane Brown to leave the field after the team presentations and before the start of the anthem. They returned when everything was over.

Miami Dolphins critics Kenny Stills and Albert Wilson knelt during a preseason opener against the Tampa Bay Buccaneers on Thursday. This photo shows one of the previous kneeling protests by Stills on September 18, 2016

Miami Dolphins critics Kenny Stills and Albert Wilson knelt during a preseason opener against the Tampa Bay Buccaneers on Thursday. This photo shows one of the previous kneeling protests by Stills on September 18, 2016

Miami Dolphins critics Kenny Stills and Albert Wilson knelt during a preseason opener against the Tampa Bay Buccaneers on Thursday. This photo shows one of the previous kneeling protests by Stills on September 18, 2016

Quinton Jefferson

Quinton Jefferson

Branden Jackson

Branden Jackson

Quinton Jefferson and Branden Jackson were two of the Seattle Seahawks players who waited in the tunnel until the national anthem ended on Thursday.

The league and the players' union have yet to announce a policy for this season with respect to kneeling down after the league initially ordered everyone to stay on the bench when playing The Star-Spangled Banner, or remain in the locker room.

No other Seahawks player protested during the anthem, nor any of their opponents, the Indianapolis Colts.

Kicking protests have been a big problem for the Dolphins in particular, with Stills performing one in most of the team's games over the past two years.

The star initially had the support of Dolphins owner Stephen Ross, but then backed off and said he wanted the players to stand up.

Wilson will enter his first season with the Dolphins, but he knelt at least once last year playing for the Kansas City Chiefs, the Miami Herald reported.

The star initially had the support of Dolphins owner Stephen Ross, but then backed off and said he wanted the players to stand up.

Offensive tackle Duane Brown also joined the protest. The NFL said recently that it would fine players who knelt during the anthem but allowed them to wait in the locker room. That decision is now being reconsidered

Offensive tackle Duane Brown also joined the protest. The NFL said recently that it would fine players who knelt during the anthem but allowed them to wait in the locker room. That decision is now being reconsidered

Offensive tackle Duane Brown also joined the protest. The NFL said recently that it would fine players who knelt during the anthem but allowed them to wait in the locker room. That decision is now being reconsidered

Dolphins coach Adam Gase told reporters this week he had not given any advice to players trying to kneel, and told reporters: "I'm not instructing anyone for anything."

Kneeling protests were provoked by San Francisco 49ers quarterback Colin Kaepernick nearly two years ago as a demonstration against social injustice.

Kaepernick praised Stills and Wilson for kneeling, tweeting Thursday night: "My brother @kstills continued his protest of systemic oppression by taking a knee tonight." Albert Wilson @ iThinkIsee12 joined him in protest. !

The protests have repeatedly provoked the ire of President Trump, who last month said players kneeling twice should be expelled from the season.

On Thursday, Dolphins defensive end Robert Quinn mounted a separate protest by raising his right fist and shaking his head (pictured)

On Thursday, Dolphins defensive end Robert Quinn mounted a separate protest by raising his right fist and shaking his head (pictured)

On Thursday, Dolphins defensive end Robert Quinn mounted a separate protest by raising his right fist and shaking his head (pictured)

Trump also criticized the $ 40,000,000 commissioner & # 39; NFL Roger Godell for not stopping the movement in a tweet on July 20, a day after the NFL said he would suspend his ban until the discussions are held.

"The National NFL Debate of the NFL is alive and well again, I can not believe it! Is it not in the contract that the players must stand firm, surrender the heart?

The Commissioner of $ 40,000,000 must now make a position. First time kneeling, out of play. Again kneeling, out of season / without pay!

Kenny Stills

Kenny Stills

Albert Wilson

Albert Wilson

Stills (left) and Wilson (right) participate in a training at the Miami Dolphins training facility in Davie, Florida, on Monday

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