Johnson has been mostly a reserve corner for the 49ers after his one-year sabbatical in Buffalo, and he played his highest number of defensive snaps since 2017 for them in 2021: 325. Johnson's good depth for the 49ers behind Emmanuel Moseley, Charvarius Ward, and Ambry Thomas. 

Johnson was joined by cornerback K’Waun Williams and RB Raheem Mostert, whose addition to the list is purely procedural. The 49ers play a must-win game versus the Rams in Week 18 so it would be a tough loss if both corners are out. With the new COVID rules in place, it's possible that neither player misses Week 18.

Johnson showed up on the injury report as questionable on Friday due to a non-injury situation, and he was downgraded to out on Saturday. It is tough timing for the 49ers, who will also be without Emmanuel Moseley (ankle, IR). This looks like a matchup to target for Joe Burrow and company. 

Johnson can play some corner in a pinch, but he's being signed as a core special teamer. The former fourth-rounder has spent six of his eight NFL seasons with the Niners. The front office still has a lot of work to do filling out the cornerback depth chart.