Lenoir (knee) has been ruled out of Sunday's Week 13 matchup against the Bills, Lindsey Pallares of the 49ers' official site reports.
Lenoir underwent an MRI on his knee Monday and didn't practice at all this week. His absence Sunday will mark the first regular-season contest he's missed his rookie 2021 campaign. Though Lenoir being sidelined Sunday will undoubtedly be a blow to San Francisco's secondary, the team will be getting back Charvarius Ward (personal) from a three-game absence.