Defensive line
DE Dee Ford
DT Arik Armstead
DT Solomon Thomas
DE Nick Bosa
The 49ers have managed to maintain a lot of their depth on the defensive line despite losing Buckner to the Colts in a trade. We went with a sub package for the starting lineup since they’ll likely be on the field the most. Thomas, the former No. 3 overall pick, will get plenty of opportunities to rush the passer from the interior, which is where he’s at his best.
The base defense is where the team really misses Buckner. Ford leaves the field with Armstead at end, DJ Jones plays the tackle spot vacated by Buckner, and Thomas is probably replaced by Jullian Taylor, although Kentavius Street and Kevin Givens may also get a shot to start. Either way, there aren’t a ton of reliable options for the 49ers, which makes a defensive tackle a strong possibility early in the draft.
Linebacker
WLB Kwon Alexander
MLB Fred Warner
SLB Dre Greenlaw
It stands to reason the 49ers start the season the same way they did last year with all three players on the field in base and Greenlaw exiting in sub packages. However, Greenlaw played very well in Alexander’s role after Alexander went down with a pectoral injury in Week 9. There’s a world where Greenlaw gets the Will linebacker job and earns a lion’s share of the snaps alongside Warner.