Injury roundup: Thomas Rawls placed on IR

The 49ers' offensive line situation was already grim heading into the season, but they took solace in knowing that at least some of their better players, like guard Alex Boone, would be there to see the team through a difficult transition.

But Boone might have played his final games in San Francisco. Per NFL Media Insider Ian Rapoport, Boone suffered an MCL sprain and is done for the season. He will not need surgery, via source who has spoken to the player.

He'll now turn his focus toward free agency. Boone held out prior to the 2014 season and eventually won an arm wrestling contest with the 49ers' brass, convincing them to roll future incentives into his salary for that season. Rapoport reported that Boone's contract stipulates he can't be franchise tagged or transition tagged, so he almost certainly will become a free agent in March.

The 28-year-old was mentioned in several trade talks at the beginning of last season, especially after the guard market dried up and teams were left with less-than-desirable starting options.

Richie Incognito, J.R. Sweezy, Mike Harris, Jeff Allen and Byron Bell are also slated to hit free agency in 2016.

Here's some more injury news from Tuesday:

1. Seahawks breakout running back Thomas Rawls was placed on injured reserve. He fractured his ankle in Sunday's win against the Ravens after emerging as a top running back in the league in place of an injured Marshawn Lynch. Rawls won't be back for a potential Seattle postseason run.

2. Bears wideout Kevin White won't come back this season. The rookie will remain on the PUP list with the shin injury that has kept him out of the lineup all season. He also won't be able to practice with the team.

3. Carolina Panthers tight end Greg Olsen did not suffer any significant injuries in Sunday's blowout win over the Falcons, via Rapoport. Olsen left the game early after landing awkwardly and bending his knee.

The Panthers were cautious with the veteran tight end, who has been a pace setter for the Panthers offense all season long. Olsen already has 108 targets on the season and is closing in on a second straight year with more than 1,000 receiving yards.

4. Browns receiver Brian Hartline was placed on injured reserve after suffering a broken collarbone in Sunday's win over the Niners. The wideout had surgery on Tuesday.