The San Francisco 49ers, who have won three games this season, were not feeling particularly elated. Their defense suffered a significant blow in Sunday's victory over the Arizona Cardinals. Key player Nick Bosa suffered a torn ACL in his right knee and will undergo surgery and temporarily retire his nfl jersey.

Bosa, who had a sack in each of the first two weeks of the season, left the game on Sunday with a knee injury after playing just 14 snaps. The star pass rusher flashed a thumbs-down sign as he walked back to the locker room after being treated on the sidelines, foreshadowing the unfortunate diagnosis. Bosa is the team's top pass rusher, but the loss of the number 97 San Francisco 49ers jerseys for the entire season is undoubtedly a significant blow.

The 49ers' injury situation is currently concerning. With Bosa's loss, the 49ers will need rookie pass rusher Mykel Williams and veteran Bryce Huff to carry the load. Ultimately, how the 49ers' defense handles Bosa's absence will determine their performance this season.