Justin Smith has a partially torn left triceps, according to a report by the Sacramento Bee.
Smith has not played since he was injured in the 49ers' Sunday night win over the New England Patriots on Dec. 16.
[MAIOCCO: Smith's return tied to regaining strength]
According to the report, the injury will likely require offseason surgery, but the team is hoping Smith can "can tolerate the pain enough to be effective during the playoffs."
Following the win over the Patriots, head coach Jim Harbaugh was asked is Smith's injury was similar to the injury that landed OLB Parys Haralson on the injured reserve and ended his season.
“No, seems to be two different things,” Harbaugh responded.
Haralson's injury was a torn triceps.