Breaking down the 49ers’ dominant rushing attack against the Packers

No matter where Kyle Shanahan goes and regardless of who’s in his offensive backfield, his rushing attack continues to dominate opposing defenses. With the 49ers’ starting running back down and a backup quarterback managing the offense, San Francisco is the fourth-best rushing team based on total yardage and tied for first in the NFL based on yards per attempt.

Running backs Matt Breida and Raheem Mostert continued to do damage this past Monday night in Green Bay, rushing for 174 yards on 30 attempts and giving the 49ers’ a chance for a victory at the end of the game. Breida played through an injury, still racking up 61 yards and a touchdown. Mostert was the star, adding 87 hard-fought yards, including a 26-yard breakout run.

Shanahan chose to ride with his speedy, quick-hitting backs, rather than go with bruising Alfred Morris on Monday, who only saw one rushing attempt, which was taken back due to a 49ers’ penalty.

The key to their rushing success? Shanahan’s play design and a strong run-blocking offensive line. To put into perspective the type of season that the 49ers’ offensive line is having, let’s turn to Pro Football Focus’ metrics. In their Week 6 edition of “Team of the Week,” three 49ers’ linemen were listed: Tackles Joe Staley and Mike McGlinchey and guard Laken Tomlinson.

Staley finished Monday night with an 88.3 grade, while McGlinchey led all rookies and Tomlinson ended up slightly behind with a 79.4 grade. What kind of success are the 49ers’ running backs having? Here are just a handful of plays where Breida and Mostert are breaking free.

On the very first play of the game, Staley and fullback Kyle Juszczyk hold up their blocks extremely well, opening a hole for Breida to gain seven yards. Especially on first down, if San Francisco can gain at least five yards, it opens up the entire playbook for Shanahan on the later downs.

Mostert follows Juszczyk — who’s highly underrated in his run blocking — and gains eight yards on this play. At the end of the play, center Weston Richburg takes down the Packers’ defender and holds his block for the entirety of the sequence.

On this play, the 49ers leave certain Packers’ defenders un-blocked and it seems like Breida should be wrapped up near the line of scrimmage. Instead, the second-year tailback shows off ridiculous burst getting to the corner and breaks it out for an eight-yard gain.

Here’s where Shanahan’s genius comes into play. Knowing full well that the Packers will bite on wide receiver Marquise Goodwin’s speed, he brings the wideout across the formation. Instead quarterback C.J. Beathard hands it off to Breida, who’s able to break it through the hole for seven yards.

Here’s the 49ers’ best run of the evening, as Mostert shows off his quickness and turns the simple play into a 26-yard gain. Richburg has a fantastic block of Packers’ defensive lineman Kenny Clark and it turns into the key catalyst for the play.

Another play, another gigantic hole to run through. Shanahan’s play design along with the 49ers’ line could make me look like a productive running back. Tight end George Kittle rushes out and takes out the edge defender, allowing Breida to turn up field and move the chains.

One more time for 17 yards, as Goodwin and Juszczyk hold their blocks on the edge for just enough time to allow Mostert to sneak through. Seems like a simple draw play and it allows the 49ers to gain easy first downs. When the defense is tired in the second half, nothing like a mauling offensive line that can absolutely take over the game.

The biggest takeaway from all this rushing success is that I can’t wait for running back Jerick McKinnon to return completely healthy to this team. His combination of straight-line speed and shiftiness along with this cohesive offensive line could absolutely wreak havoc on opposing defenses.

The Rams’ run defense is ranked 15th in the NFL, so expect a lot of the same on Sunday against Wade Phillips’ defense. Shanahan should continue to lean on his ground game, allowing Beathard to be more comfortable within the offense.