Greenlaw (Achilles) is listed as questionable ahead of Thursday night's matchup against the Rams, Eric Branch of the San Francisco Chronicle reports.
Greenlaw was designated to return from injured reserve Nov. 27 and practiced in full capacity Wednesday, suggesting he's ready to return for the 49ers' divisional matchup Thursday night. However, the Arkansas product remains on the reserve/PUP list and must be activated to the San Francisco's active roster in order to play in Week 15. If he's unable to suit up, expect De'Vondre Campbell to serve as one of the 49ers' top inside linebackers.