Film Recap: Pulling out mistakes by 49ers defense in Week 1 loss to Vikings

Kicking off the 2018 season, the 49ers defense looked to take advantage of an injury-riddled Vikings offensive line with their trio of first-round draft picks, Arik Armstead, DeForest Buckner, and Solomon Thomas. The defense held strong for most of the game. Buckner led the way with 2.5 sacks. Linebacker Fred Warner in his rookie debut had 12 tackles of his own, with a forced fumble and a near interception. The defense itself fared well only giving up 17 points to a loaded Vikings offense. Minnesota running backs combined for 27 carries for 82 yards. That’s 3.02 yards per carry. Not bad, at all.

The issue with the backs was more in coverage. With Brock Coyle filling in for Reuben Foster, he had his hands full trying to contain Dalvin Cook in space. The Vikings identified Coyle as the weakness and attacked his area on the first play of the game.

One strength of Foster's game is how quickly he diagnoses plays and attacks the player like his life depends on it. Here you can see Coyle is just a tad bit too late, and because of Cook’s speed, San Francisco gave up an easy nine yards. It was a designed play to give the ball to Cook in space, with tight end Kyle Rudolph and receiver Adam Thielen as lead blockers.

Even with all the additions to the 49ers defense, they still have areas where they can improve. The 49ers traded strong side linebacker Eli Harold to the Lions. He was a player known for setting the edge in the run game. Here you can see new SAM linebacker Mark Nzeocha fail to set the edge, allowing Vikings running back Latavius Murray to get around the corner for a 6-yard gain.

Small gain on the ground, but if the 49ers aspire to be that smothering defense, they need to consistently do all the little things well. As the season goes on, you would like to see Nzeocha force that back inside to Buckner and flowing inside backers Foster and Warner.

On several occasions the 49ers also displayed really poor tackling.

Now maybe this is just a Week 1 issue. With teams playing their starters less and less during preseason, tackling early in the season was a problem around the league. The 49ers were no exception. As you can see, the Vikings broke a number of tackles, including on this Laquon Treadwell play on 1st-and-15 that resulted in a first down after poor tackling attempts by 49ers defenders, starting with Brock Coyle.

The 49ers safeties are usually sure tacklers, but on one play both Tartt and Colbert whiffed on trying to bring down Dalvin Cook who picked up 13 yards.

Cook was slippery. And on his longest run you could see players standing around thinking someone else was going to bring him down. Fortunately for the 49ers, Warner came from behind to poke the ball out and force the only takeaway of the game for the 49ers.

And lastly: late in the fourth quarter the Vikings had a 4th-and-1 from mid-field. They lined up and did the dummy snap count motioning several players clearly to just draw the 49ers offsides. I think everyone in the stadium and those who watched the game live knew that there was no way the Vikings risk running the ball knowing that if they failed they’d hand the ball back to the 49ers with great field position in a one score game.

It seems everyone but Thomas and Armstead knew. Thomas is taking all of the blame but both Thomas and Armstead jumped offsides with one second left on the play clock. Classic boneheaded mistake, and it cost the 49ers dearly.

Bad tackling is usually a sign of a bad defense. The 49ers need to adopt a more swarming-to-the-ball culture; and in turn, the entire defensive unit will flourish. Contrary to popular belief, the 49ers do have a lot of talent on defense and they can be more consistent with doing the most basic things, like tackling.

This defense can be very scary by the end of the year just in time for a playoff push. There were plenty of fixable mistakes on both sides of the ball. In the coming weeks we will find out more about who the 49ers are. A wounded Lions team flying into San Jose on a short week might be just what the 49ers need to get on track.

Media courtesy USA Today Sports Images, NFL

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