Throughout the majority of Robert Saleh’s tenure as defensive coordinator with the 49ers, the coverages in the secondary were pretty basic. Offenses knew they would be facing primarily zone coverage, mostly Cover 3 and Cover 4 with man coverage thrown in every once in a while.
Some of that was due to philosophy, and some was out of necessity.
The 49ers defensive philosophy through the first three seasons under Saleh was to try and keep everything in front of the secondary to reduce the possibility of giving up explosive plays by playing the zone coverages mentioned earlier and disrupting the quarterback by rushing with only the four defensive linemen.
In the first couple of seasons, the defense wasn’t very good. Most of those struggles could be traced back to the lack of pass rushers. That changed in 2019.
Following a dismal 2018 season, the 49ers made a couple of moves that would drastically improve the defense. The first was trading two second-round draft picks to the Kansas City Chiefs for Dee Ford. While Ford’s total number of snaps in 2019 was reduced due to injuries, when he was on the field the effects were noticeable.
In addition to Ford, San Francisco used their first-round selection to add another pass rusher, Nick Bosa, who would go on to be named NFL Defensive Rookie of the Year with nine sacks in his rookie campaign.
With Ford and Bosa and the rest of the 49ers defensive line harassing opposing quarterbacks, the 49ers secondary flourished. After forcing only two interceptions for all of 2018, the 49ers were able to force 12 in 2019 on the way to a Super Bowl berth.
In 2020, injuries limited Ford and Bosa to only five quarters. With Ford and Bosa on the sidelines, the 49ers pass rush became nearly nonexistent, dropping from 48 sacks in 2019 to only 30.
Due to the inability to generate a pass rush with just four players, Robert Saleh was forced to use more blitz packages than any of his first three seasons in San Francisco. And for the most part, the changes worked.
A big part of the additional blitz packages working was the ability of Jason Verrett to play man coverage when he replaced Richard Sherman in the starting lineup.
With Saleh moving on to become the head coach of the New York Jets, there are a number of questions about how new defensive coordinator DeMeco Ryans might change up the 49ers defensive attack.
The selections of cornerbacks Ambry Thomas and Deommodore Lenoir in the draft may have provided the first signs of the potential changes.
Adding Thomas and Lenoir provided two backups with the ability to step in and keep the defense the same should Verrett go down with injury. Both excelled while playing primarily in man coverage during their time in college.
With Nick Bosa set to return from injury, and Samson Ebukam in line to fill Dee Ford’s role on the other side, the expectation is that the pass rush will return to what it was in 2019. However, if Bosa takes some time to get back up to speed and Ebukam doesn’t meet expectations, the focus on man coverage in the secondary will allow Ryans to build upon the pressure packages that were utilized last season to keep the defense playing at a high level.