No. 3: DeForest Buckner
That honor would belong to this player right here. There are few words to describe how valuable DeForest Buckner is to the 49ers. He’s the lifeline of the defensive line and is easily the best player on that side.
Buckner ranked sixth among interior defensive linemen, according to Pro Football Focus. He had 52 pressures and was the force behind the pass rush. When Buckner left the field, the 49ers went from 11th to last in the league in pressure rate.
But the main reason Buckner is so important is that he rarely left the field. He played almost 80 percent of the defensive snaps this year. To lose Buckner is to create a giant hole on the defensive line.
Well then, why isn’t Buckner higher?
The reason is that Buckner’s hole can be filled a little better than the next two players on this list. The 49ers have a bevy of defensive linemen who could help fill the large void. Arik Armstead, Solomon Thomas, and Sheldon Day, to name a few, are talented, if not productive, interior linemen who could help fill the gap. They wouldn’t be able to completely replace Buckner’s production, but they could do it better than the backups for this next player.