Jennings was held out of Wednesday's practice due to a shin injury, Cam Inman of The San Jose Mercury News reports.
Even tough Brandon Aiyuk (shoulder) didn't play last Thursday against the Giants, Jennings didn't experience an appreciable jump in playing time and matched his season high in targets with three, which he turned into two catches for 31 yards. As the 49ers kick off Week 4 prep, Jennings and Deebo Samuel (ribs/knee) were sidelined, while Aiyuk was a limited participant. With the team's top three wide receivers all battling injuries to some extent, the position group will be one to watch as Sunday's game against the Cardinals approaches.