The biggest knock on the 49ers' defense is that it cannot contain mobile quarterbacks to save their lives. That mobile quarterbacks are its kryptonite.
Of course, every defense has its struggles with mobile quarterbacks. That isn't a weakness unique to the 49ers.
Regardless, it is their Achilles heel on defense, which is something that the Patriots will look to exploit in their Week 7 matchup with the 49ers. Patriots' offensive coordinator Josh McDaniels has been using Cam Newton heavily as a primary runner. He'll certainly look to continue this style of attack as the 49ers have a history of struggling against mobile quarterbacks.
However, this Sunday's matchup will be different for the 49ers in terms of defending against a mobile quarterback. In fact, I am willing to go as far as to declare that the 49ers will have success defending against Newton's mobility.
Throughout all of the games where the 49ers faced mobile quarterbacks dating back to last season, the quarterbacks that hurt them the most were fast or quick. Players like Kyler Murray, Lamar Jackson, Russell Wilson and Carson Wentz.
As great of a player that Newton is, he doesn't have the same speed that made him a killer threat five years ago mobility wise. He will always have that threat of his legs because you just don't know whether he is going to toss it up or take off with it.
But Newton's game now as a runner is aggressive. That plays into the 49ers' strengths. Speed kills and is impossible to replicate and account for, but aggressiveness is something the 49ers excel at. The 49ers' defense is one of the better defense's out there who can lay the wood. Newton does not shy from contact nor does he just look to bounce it outside to the sideline. He will stay in the flurry of blocking bodies and take off with it.
When he does that, Fred Warner or even Dre Greenlaw will be there to snuff him out. Newton is not outrunning Warner or Greenlaw. The speed that these two have, especially laterally, is absurd. They won't wait on Newton to already be full stride to breakaway. They will be there to meet him at the line of scrimmage. Sunday's game against the Patriots is a perfect example of why the 49ers should feel fortunate they do not have Kwon Alexander because Newton would absolutely bully him via stiff arm or even truck him.
Another reason why Newton's mobility will be ineffective is because of his throwing woes from last week. Newton has been pretty inconsistent as a passer this season. It is as if he used up all his greatness against the Seahawks on Sunday Night Football.
San Francisco's defense is strong in pass coverage, which is pretty nuts to say, but it is definitely its greatest strength defensively now. Newton will have fits of where to go with the ball. That is where I expect him to just want to run with the ball and make something happen. Even Josh McDaniels will start to feel that having Newton run the ball is their best approach.
The only way the 49ers' defense starts to get killed by Newton on the ground is if he is making some sweet throws. That will put the defense on edge and hesitant to commit to attacking Newton. It is definitely possible that can happen, but I think this is a game where the 49ers make a concerted effort to shutdown a quarterback's mobility.