SANTA CLARA, Calif. -- While no move has been made official yet, San Francisco 49ers coach Kyle Shanahan made it clear Friday that linebacker De'Vondre Campbell has played his last snap for the team.

Campbell's decision to not play in Thursday night's loss to the Los Angeles Rams angered Shanahan and many of his teammates. After the game, Shanahan and multiple players made it clear that Campbell's actions were unacceptable, with cornerback Charvarius Ward going so far as to say Campbell is "probably going to get cut soon."

As of Friday morning, the Niners had not determined exactly how they will part ways with Campbell, but Shanahan said he didn't expect Campbell to be on the team in Week 16 and beyond.

"We're working through the semantics of exactly how to deal with it," Shanahan said. "But I mean you guys heard from me last night, you guys heard from our players, his actions from the game, it's not something you can do to your team or your teammates and still get to be a part of our team. We're working through exactly the semantics of it right now, but we'll handle the situation appropriately."

The most obvious move would be to outright release Campbell, making him an unrestricted free agent and free to sign with another team immediately. There are, however, other options the Niners can explore, such as a suspension without pay for conduct detrimental to the team.

Campbell signed a one-year, $5 million contract with the Niners in March, meaning he will again be an unrestricted free agent after the season regardless of what the 49ers decide to do now. When Campbell signed, the Niners envisioned him as a placeholder for Dre Greenlaw, the team's starting weakside linebacker who was working his way back from a torn Achilles suffered in Super Bowl LVIII.

A deal with Campbell was struck after another veteran linebacker, Eric Kendricks, agreed to sign with San Francisco before backing out to go to the Dallas Cowboys. With Greenlaw still recovering for the first 13 weeks, Campbell started 12 games and played 90% of the defensive snaps with 79 tackles, including three for loss, and two passes defended.

"We were needing a starting caliber linebacker to fill in for Dre until he could get back," Shanahan said. "We didn't know how long that would be. I thought he had some ups and downs throughout the year. I thought he started off slow. I thought he got more used to our defense and how we expected people to play, and I thought he improved throughout the year."

Greenlaw's return Thursday night offered an immediate spark for a Niners defense that held the Rams without a first down through the first quarter and just three points in the first half. But Greenlaw began dealing with some knee soreness in the third quarter, which is when the Niners asked Campbell to enter the game.

According to Shanahan, Campbell actually had been asked to enter the game in the second quarter when strong side linebacker Dee Winters departed with a neck injury. Demetrius Flannigan-Fowles had to step in for Winters after Campbell told the coaching staff he didn't want to play.

Shanahan said Friday it wasn't until the third quarter that he circled back to Campbell and found out for himself what was happening. Shanahan said Campbell was not by his teammates and was "distant from everyone" when he addressed him.

"I didn't notice until the third quarter when Dre came out and Dee went in and then I got on the defensive headset and asked what was going on," Shanahan said. "And then the coaches told me and then I addressed De'Vondre and found out. It was pretty simple to see how he was and then we moved on with our life after that."

Shanahan added that he did not tell Campbell to go to the locker room in the fourth quarter, a walk that was shown on the television broadcast as it happened. Shanahan added that he wasn't sure what led to Campbell going to the locker room but "once I found out he wasn't playing, I moved on to people who we could count on."

With Campbell on his way out, the Niners will likely need to add another linebacker to the roster. Shanahan said Friday that Greenlaw (knee soreness) and Winters (neck) will be day-to-day when the team returns to practice next week.

But assuming Greenlaw is able to recover well, he will continue to hold down his usual starting spot. For his part, Greenlaw said after the game that he didn't really know what was going on with Campbell but didn't seem too concerned about it.

"He didn't want to play," Greenlaw said. "I guess if he didn't want to play, you ain't gotta play. So, he didn't want to play."