The 49ers are under immense pressure this year after failing to qualify for the playoffs in 2024. Kyle Shanahan released and traded talented players like Deebo Samuel and signed an extension with Brock Purdy. But amid all this, the defense got left behind. They are still 9th in the league after week 3. But, as the rest of the league is catching up to them, the coach is looking for a trade that might improve their chances significantly.

According to the NFL rumor mill, the coach is eyeing the Bengals DE Trey Hendrickson to improve his defensive lineup. And the Niners understand that Hendrickson will not come cheap. But they also know that the pass rusher brings 8 years of experience with him. In August 2025, Hendrickson initially held out from the training camp. But the Bengals somehow negotiated a 1-year extension of $30 million, a $14 million raise from his previous contract. But there’s a key input for Kyle Shanahan.

Hendrickson and the Bengals discussed a two-year, $79 million extension, enough to rank him among the top three pass rushers in new money. Combined with his original $16 million base salary in 2025, that would’ve totaled $95 million over three years. But here’s the catch. Only $33 million was guaranteed, and none of it beyond 2025. Hendrickson wasn’t having it.

But on the field, he hasn’t slowed down. He recorded 17.5 sacks in both 2023 and 2024, leading the league in 2024, and earned spots on the AP All-Pro team and his fourth consecutive Pro Bowl. Those numbers aren’t just stats; they’re leverage, proof that he can dictate games, disrupt quarterbacks, and force offensive coordinators to adjust in real time.

Now, Kyle Shanahan faces a challenge of balancing performance and money. And the Bengals will also try to free up cap space. The pass rusher also faces pressure as the entire league is watching him. It’s all happening while the Niners are dealing with major injuries.

Kyle Shanahan reveals major Nick Bosa injury update

On September 21, 2025, during a Sunday night showdown against the Arizona Cardinals, the San Francisco 49ers lost their defensive cornerstone. Nick Bosa, the 27-year-old All-Pro defensive end, suffered a torn ACL in his right knee and will miss the remainder of the 2025 season.

The injury occurred late in the first quarter. Bosa was rushing quarterback Kyler Murray from the left side when he engaged with left tackle Kelvin Beachum. A double-team by guard Evan Brown sent Bosa to the ground, his knee bending awkwardly. He limped to the sideline, gave a thumbs-down to family in the stands, and was ruled out at halftime.

“You don’t just replace a guy like Nick,” HC Kyle Shanahan said Monday, September 22, during the post-MRI confirmation. “Everyone’s got to continue to get better.” Bosa, the 2022 NFL Defensive Player of the Year, has been a force since entering the league in 2019. In the first two games of 2025, he recorded 2 sacks, 8 quarterback pressures, 15 tackles, and a 21.9% pass-rush win rate.

Shanahan detailed the conversation with Bosa after the win. “He was pretty confident that he did it. You could tell walking on the field, seeing his face and could tell talking to him last night just how sure he was of it and knowing his body, and then an MRI confirmed it this morning.” A clean ACL tear with no other ligaments damaged. Bosa will undergo season-ending surgery once the swelling subsides.

However, Bosa is no stranger to ACL tears. He partially tore his right ACL in high school and tore his left ACL in Week 2 of the 2020 NFL season. The 49ers now face a major defensive test. With Bosa sidelined, players like rookie Mykel Williams, Bryce Huff, Yetur Gross-Matos, and Sam Okuayinonu will need to step up.

The Niners are also managing other injuries. QB Brock Purdy (toe) is gradually increasing practice workload. Since entering the NFL, the 49ers are 65-32 with Bosa playing and 6-12 without him. It’s a challenge that will test every player on the roster.