One day after the Niners activated Coleman, who had spent the previous five games on injured reserve with a sprained knee, he was unable to make it through the first quarter of their game against the Seattle Seahawks.
With 5:42 left in the first quarter, Coleman took a handoff to the left side and gained 12 yards on second-and-10. But Coleman got up slowly and hobbled to the sideline immediately after the play.
At halftime, the Niners said Coleman was questionable to return with a knee injury, and they ruled him out soon after. Coleman had three carries for 20 yards before departing.
The loss of Coleman left the Niners with just rookie JaMycal Hasty and veteran Jerick McKinnon available at running back. McKinnon has had a limited role in recent weeks after a heavy workload early in the season, leaving Hasty to get many of the opportunities.
Hasty scored his first NFL touchdown in the second quarter.
The 49ers entered Sunday's game without starting running back Raheem Mostert and backup Jeff Wilson Jr., both of whom are on injured reserve with high ankle sprains.