49ers rookie defender being evaluated for concussion vs. Browns

The San Francisco 49ers have taken several hits on the defensive side of the ball this season, especially at linebacker with Fred Warner out for the season and Tatum Bethune out with a high-ankle sprain.

In the first quarter of their Week 13 battle with the Cleveland Browns on Sunday at Huntington Bank Field, the 49ers lost another linebacker when third-round pick Nick Martin was taken back to the locker room for evaluation of a concussion.

Without Warner, Bethune and Martin, San Francisco's linebacker room has just Dee Winters, Curtis Robinson, Luke Gifford and Jalen Graham, who was called up from the practice squad for this game.

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This article originally appeared on Niners Wire: 49ers LB Nick Martin suffers injury vs. Browns in Week 13