The 49ers discussion all offseason has revolved around the quarterback position.
But quarterback is the deepest position on the team. Even the third-string quarterback, Josh Rosen, has lots of talent. So if Jimmy Garoppolo gets injured again, the 49ers should be able to win without him. Plus, Trey Lance will take his job soon anyway, probably no later than the Bye week, maybe as early as Week 1.
Which means the most important player on the 2021 49ers is not a quarterback. The most important player is Nick Bosa.
Bosa is the 49ers pass rush. Bosa is the one player on the defensive line opposing offenses have to double team. Theoretically, he makes Arik Armstead, Javon Kinlaw and Samson Ebukam better.
So if Bosa plays as well as he played as a rookie in 2019, the 49ers should have a terrific defense, perhaps a better one than last season when he missed all but two games with his second torn ACL. And last season's defense ranked No. 5 out of 32 teams.
But if Bosa does not perform up to his usual standard, if he's inconsistent in his first season back from an ACL surgery or gets injured again, which is his pattern, the 49ers pass rush could really suffer. And then the entire defense could be in trouble, because Robert Saleh won't be there to make magic. He's the New York Jets head coach now. And his replacement, DeMeco Ryans, seems talented, but never has called plays before.
Bosa has to make up for the loss of Saleh. Bosa has to play like a Pro Bowler. Bosa will determine how far the 49ers will go.