The 49ers are firing De'Vondre Campbell, effective immediately, after the linebacker refused to take the field Thursday night when he called in, apparently over some ego thing.

De'Vondre Campbell didn't give a reason for why he wouldn't leave the bench Thursday when, in the third quarter, he was being called in to relieve fatigued starting linebacker Dre Greenlaw — who had just entered the season in this game after a torn Achilles tendon. But many have surmised that Campbell, who started in 12 of the team's 13 games this season, was upset about being replaced by Greenlaw in his first game back.

Coaches and teammates were fuming Thursday as, in this do-or-die matchup with the LA Rams, they were down, it was raining at Levi's, and their season was looking potentially doomed.

“I have never been around anybody that’s ever done that and I hope that I’m never around anybody that does that again,” said tight end George Kittle of Campbell's boycott, per Bay Area News Group.

As of Friday morning, coach Kyle Shanahan announced the team would be severing ties with Campbell, which may mean a suspension of his $5 million contract, a release from it, or a termination.

"We’re working through the semantics of exactly how to deal with it," Shanahan said during a media conference call, per the Chronicle. “You heard from me last night and the players. His actions from the game are not something you can do to your teammates or your teammates and still be part of our team.”

Shanahan reportedly found out about Campbell's boycott over his headset as he asked the defensive coaching staff where De'Vondre was in the third quarter. Campbell walked off the field in the fourth quarter to the locker room, and left the stadium before reporters could find him.

Reactions to Campbell's refusal to take the field have been universally outraged across the football world.

"If it were me, he would've been cut before he left the locker room," said ESPN's Stephen A. Smith, per NBC Bay Area. "He wouldn't have made it out of the locker room as a San Francisco 49er. I'll be honest with you: his career is in grave jeopardy. And it should be."

"You don't want a teammate like that," Smith added. "De'Vondre Campbell should be ashamed of himself. There is no excuse for what he did."

On FS1's The Facility, Emmanuel Acho also reportedly went off, saying, "I suggested De'Vondre Campbell is a double agent. I suggested De'Vondre Campbell is a traitor. The 49ers are a team, historically, an organization of toughness. Ronnie Lott, a historical great, he cut off his finger just so he could play in a game. My dear friend Marquise Goodwin, his wife had a stillbirth the day before [and] he plays in the game and catches a touchdown and prays up to the sky... Ricky Pearsall got shot and played six weeks later. Fred Warner had a broken ankle and he played the entirety of the season. Charvarius Ward lost a child and he played this season. George Kittle has ligaments being held together by a string. Dre Greenlaw tore his Achilles and played 10 months later. And all you got, De'Vondre Campbell, is a bruised ego."

Charvarius Ward had some choice words as well, saying, "If he didn’t want to play, he shouldn’t have dressed out. He could have told them that before the game. I feel like that was some sucker shit that he did. … That’s some selfish stuff to me, in my opinion. Probably gonna be cut soon."

Campbell's record on the field this season was mixed, and it would certainly seem like a stretch for another team to want him now.

Top image: Linebacker De'Vondre Campbell #59 of the San Francisco 49ers stands on the field during the first quarter of an NFL preseason football game against the New Orleans Saints, at Levi's Stadium on August 18, 2024 in Santa Clara, California. (Photo by Brooke Sutton/Getty Images)