Why San Francisco 49ers Must Make Defensive Line Top Priority Under Jim Tomsula

Saying that the defensive line is the San Francisco 49ers’ top offseason priority under new head coach Jim Tomsula would seem a rather trite declaration in these present circumstances.

After all, the man replacing the recently departed Jim Harbaugh has coached that position group since coming to San Francisco in 2007. And nothing but stellar results have materialized during that time.

Look no further than a defense that has ranked fourth in rushing yards, rushing average and total yards allowed since 2007, per 49ers.com. His biography on the team’s website further details his incredible work in player development and other notable records and achievements.

So, why would Tomsula place the 49ers' established strength atop the offseason need board when wide receiver remains such a glaring deficiency on this team? Cornerback, offensive line and even tight end could rightfully merit more attention as well.

Free-agent wideout Michael Crabtree won’t be retained, Anquan Boldin is 34 and corners Chris Culliver, Perrish Cox and Chris Cook are all in need of new contracts.

Vernon Davis didn’t register any touchdowns after Week 1, Vance McDonald still didn’t produce in the passing game and Colin Kaepernick suffered more sacks than any other quarterback in 2014 due much in part to the porous play of his backup pass-blockers.

Tony Avelar/Associated Press

Defense has rarely if ever been the problem for the 49ers these past several years. The development of Kaepernick and the offense as a whole should trump all other needs.

A talented but consistently lackluster unit that ranked 29th in passing and 25th in points scored is far from secure, right?

To be sure, Tomsula must undoubtedly hire the right offensive coordinator and staff—coaches who will galvanize this underachieving group and raise it to new heights. He must also devote ample time into replacing the entire defensive staff, as Vic Fangio and Co. have moved on since Tomsula’s promotion, per David Fucillo of Niners Nation.

But when it comes to specific positions, the defensive line outranks all other areas.

According to Bleacher Report’s Matt Miller, via Fucillo, the 49ers will likely switch from a 3-4 to a 4-3 defense in 2015.

As Fucillo points out, that would entail Aldon Smith and Aaron Lynch putting their hands in the dirt as defensive ends. If Justin Smith retires, any combination of Glenn Dorsey, Ian Williams, Tank Carradine, Quinton Dial and Tony Jerod-Eddie would fill the interior tackle roles.

With Chris Borland taking over middle linebacker, Patrick Willis and NaVorro Bowman would occupy both outside ‘backer spots. Nick Moody, Corey Lemonier and, if re-signed, Dan Skuta and Michael Wilhoite would serve as the top backups in the front seven.

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Ahmad Brooks and his $9.6 million cap hit in 2015 aren’t long for San Francisco.

But even with Brooks’ impending release, this defensive front is flush with Pro Bowl bodies and highly skilled reserve personnel. Why focus so much on this area when all of those aforementioned positions stand on such tenuous ground?

Because as much as the 49ers and their fans would love to see the rise of a competent, NFL-quality offense, this team’s bread and butter lies on the defensive side of the ball.

If the Niners and their faithful desire more than eight wins and earn a postseason berth, all offseason attention must first revolve around the defensive line.

And lest we forget, everything begins and ends in the trenches.

Tomsula—and whichever assistants he hires—must hone this positional group into a well-functioning machine. In addition to acquiring any additional pieces through free agency and the draft, the coaching staff must ensure the front four performs at the highest level so that the linebackers and secondary are freed up to make plays on the back end.

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With the front line as the core of the Niners defense and said defense as the team’s fundamental strength, it follows that Tomsula must first address the new front four. He must establish what the 49ers do best before eliminating those other deficiencies.

Returning another top-five—or even top-10 defense—will lay the groundwork for at least an eight- or nine-win campaign. Evolving the offense will then push this squad into playoff contention.

San Francisco surely finds itself in a fluid situation. The hiring of new coaches and whether Tomsula can sway Justin Smith out of his potential retirement will initially take precedent moving forward as well.

But in order for Tomsula to lead a winning effort and realize that “great head coach” potential, as Smith himself so articulated, via ESPN.com’s Paul Gutierrez, he must implement a great defensive line.

And, as the saying goes, “the rest will take care of itself.”

Unless noted otherwise, all player and team stats come courtesy of Pro-Football-Reference.com. Contract information provided by Spotrac.

Joe Levitt is a Featured Columnist for Bleacher Report, waxing academic, colloquial and statistical eloquence on the San Francisco 49ers. Follow him on Twitter @jlevitt16.