San Francisco 49ers starting cornerback Deommodore Lenoir is heading into a pivotal 2026 season, according to Pro Football Focus. PFF's Bradley Locker wrote that Lenoir is one of 10 players on Super Bowl contenders who make or break his respective teams' 2026 campaign. Locker pointed to a step back in coverage and run defense as reasons for concern with Lenoir.Lenoir finished the 2025 regular season with 61 tackles (39 solo) and two interceptions across 17 starts, his lowest tackle total in four seasons as a starter. He also broke up three passes and allowed a 104.0 passer rating when targeted, per PFF, which had him at a 60.7 overall grade 65th among 114 qualified cornerbacks.It's still remarkable that the 49ers reached the divisional round given their defense finished 31st in success rate. While injuries and issues affected almost every level of the unit, Lenoir was also more ineffective than usual.Lenoir led San Francisco in defensive snaps but posted a 65.7 PFF coverage grade, good for the 62nd percentile a dip from the 74-plus coverage grades he posted in each of the previous two seasons. His 99.8 passer rating allowed still ranked 20th-highest among qualified corners, and he graded in the 51st percentile in coverage at outside corner. He was also flagged a career-high 10 times, and his run-defense grade fell to a personal low of 44.3.The 49ers added veteran cornerbacks Nate Hobbs and Jack Jones this spring, but Lenoir remains positioned to start opposite Renardo Green and Upton Stout. That trio graded as PFF's 28th-ranked cornerback unit overall in 2025, with the 25th-ranked team coverage grade.San Francisco's defense should get a boost from the returns of Fred Warner, Nick Bosa and Dre Greenlaw, along with the hiring of Raheem Morris as defensive coordinator. Lenoir signed a five-year extension with San Francisco in November 2024, keeping him under contract through the 2029 season.This article originally appeared on Niners Wire: 49ers starter entering 'make-or-break' season, per PFF