Four games into another season with a stacked defensive line and there is again concern surrounding a lack of pass rush from the San Francisco 49ers.

The 49ers, having recorded just 30 sacks in 2017, have been able to register a meager eight through the first quarter of the season, with 3.5 of those coming from DeForest Buckner. Only five teams in the league have fewer, and the disappointing pass-rushing performance from the defensive front has led to scrutiny over the Niners' decision to trim their options at the edge rusher position, a spot where they were already lacking in talent.

Having released the now-retired Elvis Dumervil and let go of free agency signing Jeremiah Attaochu, while also deciding to stash Pita Taumoepenu on the practice squad, San Francisco's options off the edge are thin.

Cassius Marsh and Ronald Blair have seen the majority of snaps off the edge on passing downs but have just a half sack between them, though Marsh did have one negated by a facemask against the Detroit Lions in Week 2.

There does not appear to be an edge rushing savior coming for the 49ers, who for their part do not appear to be overly interested in finding one at this point. Yet a formula for an improved pass rush may have been discovered against the Los Angeles Chargers, a game in which San Francisco had just one sack of Philip Rivers, as the Niners enjoyed early success pressuring Rivers with blitzes involving inside linebacker Reuben Foster.

Foster was sent twice on blitzes on the Chargers second drive. On the first he was completely unblocked on a five-man rush, forcing Rivers to hurry his incomplete throw. The second saw him force a three-and-out on a zone blitz. Marsh occupied a tackle, leaving the left guard in two minds as to whether to block Foster or Buckner. With the center opting to help the the right guard double-team Fred Warner, Foster was able to use his quickness to slip through a small gap and again hurry Rivers.


In the 49ers' most recent era of success under Jim Harbaugh, the defense flourished in part because it had two of the NFL's best pass-rushing inside linebackers in Patrick Willis and NaVorro Bowman, who combined for eight sacks in their final full season together in 2013. Foster, with his downhill closing speed and willingness to attack blockers, has the potential to make a similar impact.

Of course Foster cannot be used as a pass rusher on every snap -- his skills in coverage and as a run defender are too valuable -- and the zone blitzes on which Foster is often asked to pressure the quarterback carry inherent risks, with defensive linemen tasked with dropping into coverage. The 49ers learned that the hard way against the Chargers as Solomon Thomas was left having to deal with a complete mismatch covering Antonio Gates. However, when zone blitzes are correctly called and properly executed, they can be an excellent avenue to generating pressure.

Foster does not always have to be the one rushing the passer on interior blitzes. Safety Jaquiski Tartt boasts similar downhill closing speed and Antone Exum also flashed as someone capable of knifing into the backfield against the Chargers.

At this point, though, it appears clear that the 49ers' best hopes of capitalizing on the attention Buckner, Armstead and Thomas can draw is by looking to the talent they have in the middle of the field, rather than the limited talent they possess on the edge.