Jennings (hamstring) is listed as inactive for Sunday's game at the Rams, Lindsey Pallares of the 49ers' official site reports.
Jennings managed one limited session in practice during Week 8 prep, but it wasn't enough to play through his hamstring issue. The 49ers also are without top wide receiver Deebo Samuel (hamstring) on Sunday, so Brandon Aiyuk will be joined in the lineup by some combination of Ray-Ray McCloud, Danny Gray, Willie Snead and Tay Martin at the position. Jennings will use a Week 9 bye to heal up for the team's next game Sunday, Nov. 13 against the Chargers.