The San Francisco 49ers placed rookie running back Trey Sermon on injured reserve on Saturday.
Sermon injured an ankle in last week's 34-26 victory over the Minnesota Vikings. The move to IR means he will miss at least three games.
Sermon has rushed for 167 yards and one touchdown in nine games (two starts). He also has three receptions for 26 yards.
San Francisco also downgraded linebacker Marcell Harris (concussion) to out for Sunday's game against the Seattle Seahawks.
Niners star linebacker Fred Warner (hamstring) remains doubtful for the contest. Warner has never missed a game in four NFL seasons.
--Field Level Media