Jennings was limited in practice Thursday due to an ankle injury, Adam Caplan of SiriusXM NFL Radio reports.
Jennings dealt with an ankle concern in early August before missing the 49ers' final two preseason games due to an oblique issue. With an ankle injury listed on the team's first practice report of the campaign, he may still be dealing with the former, but he at least has a pair of chances to log a full session before San Francisco may make a call on his status ahead of Monday's contest against the Jets. If he's available Week 1, Jennings will serve as the No. 3 WR behind starters Deebo Samuel and Brandon Aiyuk due to Ricky Pearsall (chest/shoulder) being on the reserve/non-football injury list.