San Francisco passed on defensive talents, most notably cornerback Marcus Peters, to take Armstead with the 17th overall pick, and many believe such a lofty draft position was unjustified.
With only six sacks to his name through three seasons and 18 games missed through injury, it is easy to see the logic behind that argument. Yet Armstead's impact as a pass rusher is underrated.
He led the league in Pro Football Focus' Pass Rush Productivity metric for 3-4 defensive ends in 2015 and 2016. Armstead had 38 total pressures as a rookie and 21 hurries and three sacks in 2016.
Having initially been miscast by the coaching staff as a candidate for the LEO defensive end role, Armstead only had six games to showcase his abilities in a four-man front last season before injury ended his campaign.
And despite his clear potential, Armstead's long-term future now appears at risk after again being struck by injury at a time when he is in an ideal role to succeed, the 'big' defensive end, giving others the opportunity to excel and threaten his position on the team.
With a hamstring strain likely to keep Armstead out multiple weeks, the 49ers gave seventh-round rookie Jullian Taylor reps with the first-team defense after he flashed while on the third team. The versatile Ronald Blair also received practice snaps at big end and both he and Taylor have skill sets to take snaps away from Armstead with impressive preseasons.
Taylor brings some quickness as a pass rusher but also excelled as a run stopper at Temple, displaying an impressive ability to consistently stack and shed blockers and find the football.
Blair, meanwhile, has demonstrated pass-rush upside in limited action, showcasing some capability to bend round the edge, which is a skill Armstead is not known for despite his generally impressive pressure rate.
Armstead does not have much prior credit stored up with this regime and its impression of him will not improve by yet another injury. Should Taylor or Blair flash playing in his role in preseason, the 49ers would be well within their rights to wonder if Armstead is worth keeping around.
A departure does not seem imminent for Armstead after the Niners picked up his fifth-year option. However, Lynch and Shanahan have seen more of him on the sideline than they have of him pressuring opposing quarterbacks, with this latest setback continuing a worrying trend.
This regime has shown little hesitation in moving on from holdovers and if his injury issues continue into the new season and Taylor and Blair catch the eye, then it may not be too long until Armstead is added to the laundry list of cast-offs from the Baalke era.
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