Arik Armstead can be a terrific player, as we saw in 2019 when he had 10 sacks.
He also can be the invisible man, as we saw in 2015, 2016, 2017, 2018 and 2020, when he had 12.5 sacks total.
Something clicked for Armstead two seasons ago. Perhaps he turned a corner in his development, or maybe he just got to play with Nick Bosa, Dee Ford and DeForest Buckner -- three pass rushers who drew more attention from opponents than Armstead. So Armstead led the teams in sacks that season.
In 2020, the 49ers traded Buckner to the Indianapolis Colts, and his replacement, Javon Kinlaw, is not a pass rusher yet. He finished 2020 with just 1.5 sacks.
And both Bosa and Ford missed most of last season. Which means Armstead quickly became the 49ers No. 1 pass rusher, the player opposing teams game planned to shut down. And they shut him down. He finished the season with just 3.5 sacks.
But Armstead had to move to defensive end full time to help fill the absence of Bosa and Ford. And Armstead is not a good edge rusher. He's a good run-defending defensive end who lacks the speed, explosion, flexibility and technique to beat offensive tackles to the quarterback.
And to make matters worse, when Armstead rushed from the edge and generated zero pressure last season, he routinely would allow quarterbacks to escape the pocket and extend plays. So he had a negative impact on the 49ers defense.
But when he rushes from the interior, he makes a positive impact. Because he's a violent, powerful 6'7" man who can get underneath the pads of an offensive guard and forklift him into the quarterback's lap.
And that's what Armstead should do in 2021. Because Bosa should return, Ford could return, plus the team signed edge rusher Samson Ebukam. So Armstead should rush primarily from the interior, and have a big-time bounce-back season.