SANTA CLARA Demarcus Dobbs' season is over with the 49ers, who placed the special-teams standout on injured reserve Tuesday because of a right knee problem.
Dobbs was hurt when he landed awkwardly in the first half of Sunday's 27-13 victory over Miami and had to be carted off the field.
Coach Jim Harbaugh had remained optimistic that Dobbs' knee would be OK, but MRI results revealed otherwise.
Dobbs returned to action Sunday after he didn't travel for the game at St. Louis on Dec. 2 following his arrest Nov. 30 his 25th birthday on suspicion of driving under the influence and possession of marijuana. Afterward, he expressed how sorry he was about the incident.
The second-year pro had seven tackles in 12 games this year.