San Francisco 49ers: Full position grades for the 2018 season

As is the case with Robbie Gould and special teams, the play of veteran cornerback Richard Sherman elevates the grade for this unit considerably from what it would have been without him.

Sherman went the entire year without recording an interception (so did the rest of the Niners defense outside of the safety group). But that’s largely because no one threw Sherman’s way.

Just ask Pro Football Focus:

As for the rest of the Niners cornerbacks? Well, one can say there’s a lot left to be desired. Second-year pro Ahkello Witherspoon was another one of those players Brad Almquist referenced in San Francisco’s 2018 regressions. Nearly on a weekly basis, Witherspoon would either be flagged or give up a big play.

Fortunately, Witherspoon finished with a nice four-game hot streak before landing on injured reserve late in the year with a knee injury. Let’s hope that’s the trend rolling into 2019.

One of the other notable competitions to watch in training camp this year will be between nickel corners D.J. Reed and K’Waun Williams — each of whom had solid performances filling that void.

Reed is a strong candidate to take over starting duties, which would be more cost effective to San Francisco. And at some point down the road, 2018 rookie Tarvarius Moore has to be in the picture for an eventual starting boundary corner spot. Pro Football Focus gave him a season grade of 52.1, which isn’t great.

But considering he never played cornerback before entering the NFL in Round 3 last year, that’s not terrible either.