The San Francisco 49ers are in a bit of a tight spot Sunday, as they travel to Cincinnati in a pivotal matchup of two playoff hopefuls. Starting running back Elijah Mitchell missed Wednesday's practice. He was placed in the league's concussion protocol on Monday. But apparently, there are other concerns as well.

Mitchell has been a huge surprise for the 49ers this season. He was drafted in the 6th round in the 2021 NFL Draft, but was not expected to have a large role. Whereas, 3rd round pick Trey Sermon was the player out of college expected to make an immediate impact.

Sermon has struggled to even get on the field. Meanwhile, Mitchell has had a breakout season and is among the leaders for Offensive Rookie of the Year. He has 759 yards rushing and five touchdowns. Keep in mind, he has done that while missing three games with injury.

Mitchell missed two games early in the year, and then missed Week 11 also with a broken finger. Upon his return, he immediately took over as a 3-down back again, racking up 199 yards rushing and 8 catches over the last two weeks. However, he left Sunday's game briefly and was checked out by doctors.

He was cleared and returned to the game. With the news that Mitchell not only is in the concussion protocol, but also having an MRI on his knee, shows there is legitimate concern for his availability this week.

The 49ers' Trey Sermon and Jeff Wilson Jr. are both nursing injuries, leaving only JaMycal Hasty as the only healthy running back on the roster.