San Francisco 49ers: Creating the ideal starting defense in 2019

The San Francisco 49ers need a lot of help, defensively, heading into 2019. But there are a few ways to turn this unit around in a major way this offseason, and Niner Noise does this in this defensive breakdown.

San Francisco 49ers coordinator Robert Saleh’s defense was pretty misleading in 2018. On one hand, it didn’t allow a ton of yardage — 5,546 in total, which was 13th best in the NFL last year.

But on the other hand, Saleh boasted the league’s fifth worst scoring defense, giving up a total of 435 points and coming in with a record-low seven turnovers generated.

There are a number of reasons behind this. A lack of a pass rush (San Francisco had just 37 sacks last year) could explain a lot of the problems. No pass rush equates to opponents’ quarterbacks having more time in the pocket, which allows their receivers to get open, therefore avoiding would-be interceptions.

Yet Saleh’s woes don’t end there.

In order for his single-high safety, Cover 3 defense to work effectively, a quality free safety is needed. The Niners thought they had one in second-year pro Adrian Colbert, but he struggled before landing on injured reserve with a high ankle sprain.

Tack on a need there, too.

So, for the sake of some fun, Niner Noise peruses through both NFL free agency and the 2019 NFL Draft for options to turn San Francisco’s defense into one of the more formidable units this upcoming season.

Here’s how it can be done, starting up front.

Defensive Line

1-Technique Nose Tackle: D.J. Jones

3-Technique Defensive Tackle: DeForest Buckner

5-Technique “Big” Defensive End: Arik Armstead

LEO: Shaquil Barrett

Before you get upset the 49ers go with a depth guy from the Denver Broncos, EDGE Shaquil Barrett, as the starting LEO and not some top-tier pass-rusher, relax. We’ll get there.

The end of 2018 suggested the Niners are ready to turn the page on the veteran, Earl Mitchell, at nose tackle and insert two-year pro D.J. Jones instead. He played well down the stretch, and is both younger and cheaper.

Defensive tackle Arik Armstead was arguably San Francisco’s second best defender behind fellow DT DeForest Buckner, and Armstead is on his fifth-year option. His efforts against the run should be crucial against NFC West running backs like the Los Angeles Rams’ Todd Gurley, Arizona Cardinals’ David Johnson and the Seattle Seahawks’ Chris Carson.

Barrett is equally balanced against both the pass and the run. And while his sack totals aren’t huge, one has to note he’s buried on the Broncos’ depth chart behind EDGEs Von Miller and Bradley Chubb.

KNBR 680’s Brad Almquist described the would-be fit:

"Barrett entered the NFL as an undrafted free agent in 2014 and has been a steady contributor on the Denver defensive line since. He has 14 sacks in four seasons. Barrett, stuck behind Von Miller and Bradley Chubb, may want greater opportunity elsewhere entering 2019. On paper, he’s a fit for the 49ers."

This would likely force the Niners’ 2017 first-round NFL Draft pick, Solomon Thomas, into a reserve role again. But good defensive line rotations are key in today’s NFL, and he’ll get his snaps.