On Tuesday of last week, Arik Armstead was placed on injured reserve to recover from a shoulder injury he suffered in training camp. Expectations were high for him coming into this season, having put up 19 tackles and 2 sacks in very limited action his rookie year. Once news of the injury came out and after he said he would play through the injury, it almost felt like a matter of "when", rather than "if". Even in a semi-incompacitated state, he nearly surpassed his tackle total from his rookie year. So now that he is able to spend time recovering, where does that leave the defensive line? Let's look at the first game post-IR announcement and see what formations and player groupings were used and try and predict how the line will do in his absence.
The 49ers early on used a 3 man front of DeForest Buckner, Mike Purcell, and Quinton Dial for first and second downs. They relied heavily on OLB play from Brooks and Harold to try and disrupt the offensive line, bottle up runners, and generate pressure. They used an interesting set of blitzes for 3rd downs as well. On the first drive they kicked Buckner inside, with Ronald Blair as an end and Ahmad Brooks, Eric Reid, and Gerald Hodges blitzing. On 3rd and 4 it resulted in an incomplete pass.
As fun as it was seeing preseason superstar 2015 Mike Purcell on the field, having him in as a NT does not really play to his strengths. He's a high motor guy with a nose for the ball. As such, when Glenn Dorsey, still recovering from a torn ACL, came out into the field, the defensive line looked much more stout. Dorsey's ability to absorb blockers led to the 49ers keeping David Johnson to a low 55 yards. This was the first time since week 1 the 49ers have kept a running back below 100 yards rushing.
At the time Armstead was placed on IR, the 49ers also claimed DT Chris Jones off of waivers from the Miami Dolphins. Drafted in 2013 in the 6th round by the Houston Texans, Jones was cut by Houston and picked up by the New England Patriots. He started 25 games, and registered 88 tackles, 10 sacks, and 1 fumble recovery. Jones definitely has some talent and with a coach like Jerry Azzinaro and players like Buckner and Dorsey around him, he could be a starter who helps solidify the line for at least the rest of this season.
So where does all this leave the defensive line? Most likely a lot of what we have seen. A rotation of Purcell and Dorsey on the inside with Dial and Buckner flanking them. Specialized blitz packages that will bring players like Hodges and Blair onto the field and will help them gain experience. The real question will be how Chris Jones will figure into all of this. The most important takeaway will be that Armstead will be able to get some much deserved recover time and will hopefully come back stronger than before.