NASHVILLE, Tenn. -- Tennessee Titans wide receiver Rishard Matthews appears to be absolute in his decision to stay inside during the national anthem, saying he is willing to give up his profession rather than being forced to change his protest over social issues.

On Thursday afternoon, Matthews was asked by Matt Parker, a local Nashville producer, via Twitter if he would continue to remain in the locker room during the anthem if the NFL created a rule requiring players to stand or face a penalty.

"No, I will be done playing football," Matthews responded.

Matthews, who hit the field for the Titans' Thursday afternoon practice, quickly deleted the tweet. He was not available for reporters during locker room availability Thursday.

Matthews, whose father served 23 years in the Marines and whose brother, another Marine, died in Afghanistan two years ago, has been vocal in his stance against racial injustice and police brutality. His protest was launched shortly after President Donald Trump's attacks toward NFL players who choose to protest. Matthews previously refrained from protesting in respect of his brother, but after Trump's comments, he said his brother would understand his intentions going forward.

The NFL and NFL Players Association released a joint statement Wednesday confirming that there has been no change to the policy that recommends, but doesn't require, players to stand for the anthem. Commissioner Roger Goodell, NFLPA executive director DeMaurice Smith and player leadership will attend league meetings next week to discuss how to progress on social issues and discuss the subject of protesting during the anthem in a larger scale.

The Titans remained in the locker room during the anthem before their Week 3 game against the Seattle Seahawks. Matthews, the Titans' leading receiver, has remained in the locker room alone during the past two games while the rest of the team stood for the anthem.

Tight end Delanie Walker said he received death threats after the Seahawks game after stating that fans who felt disrespected by athletes using their platform to protest don't have to come to games.

Last month, Matthews pledged to donate $75,000 to organizations that support oppressed communities. He has begun following the path of college teammate Colin Kaepernick, who led the charge of NFL players protesting racial injustice and police brutality in this manner.

"Moving forward, I don't want this to be a publicity stunt," Matthews told ESPN last month. "I don't want to take away from what the whole protest is about, which is oppression, police brutality and inequality in this country. I fully stand with my brother Kap, and I plan to continue to do that."

Matthews, who turned 28 on Thursday, is in the second year of a three-year, $15 million contract signed in the 2016 offseason.

"I'm tired of hearing, 'Stick to sports.' It comes down to right and wrong in this world," Matthews told ESPN last month. "If you see wrong and don't say anything, that's wrong. As minorities, what do you want to happen before we say anything? They tried to have a silent protest, and look what happened. It's your right to stand or sit down. You have that right, that freedom of speech, and you're not allowing that to happen."