The focus on the San Francisco 49ers this offseason has been primarily on quarterback. However, there could be another concern for the team.

He was the second overall pick in the 2019 NFL Draft and has been an enormous part of the team's recent resurgence. As a rookie, San Francisco 49ers defensive end Nick Bosa played in all 16 contests and these past two seasons, he's been around for 17 and 16 games, respectively.

It's worth noting that he missed all but two games in 2020. That season, the Niners fell to 6-10. In his other three years with the club, the team reached Super Bowl LIV in 2019 and the NFC Championship Game in both 2021 and '22.

In four seasons and a total of 51 regular-season contests, the former Ohio State standout has totaled 43.0 sacks and eight forced fumbles. He's played in a total of nine playoff contests and has eight QB traps. Bosa is the reigning NFL Defensive Player of the Year.

He's also entering the final year of his rookie deal. He's due to make $17.859 million in 2023 after the team picked up his fifth-year option. Apparently, that is not satisfactory for the three-time Pro Bowler and 2022 All-Pro.

In 2022, the 49ers allowed the fewest points in the league (277), a feat last achieved by the franchise in 1984. Kyle Shanahan's squad allowed the fewest total yards in the league and only Titans gave up fewer rushing yards per contest. Bosa finished with an NFL-best 18.5 sacks, somewhat close to half of the team's total (44) in '22.

General manager John Lynch has assembled quite the talented unit. Along with Bosa, there are All-Pros in linebacker Fred Warner and safety Talanoa Hufanga. Former Eagles defensive tackle Javon Hargrave was signed this offseason. There is a new defensive coordinator in Steve Wilks, who takes over for DeMeco Ryans.

That being said, this would be a much different defensive unit without the exuberant Bosa. Then again, it's late July and not early September. It will be interesting to see if this situation drags out at all.