For the first three weeks of the 2025 NFL season, the San Francisco 49ers looked like one of the NFC’s most complete and dominant squads. Their blend of offensive balance and defensive muscle had fans already dreaming of another deep postseason run. In Week 4 at Levi’s Stadium, though, those dreams took a sharp reality check. Against a scrappy Jacksonville Jaguars squad, the 49ers beat themselves. Turnovers, poor execution, and glaring weaknesses across multiple positions combined for their first loss of the season. It was a painful reminder that the margin for error in the NFL is always razor thin.

Game recap

San Francisco 49ers head coach Kyle Shanahan on the sidelines against the Arizona Cardinals during the second half at Levi's Stadium.
Mandatory Credit: Cary Edmondson-Imagn Images

The 49ers dropped their Week 4 matchup to the Jaguars, 26-21, in front of a stunned home crowd. San Francisco gave the ball away four times, including three turnovers that Jacksonville quickly converted into 17 points. The backbreaker came on special teams when Parker Washington returned a punt 87 yards for a touchdown. That gave the Jaguars momentum that never wavered.

Christian McCaffrey once again did his part. He racked up up 141 yards from scrimmage. Meanwhile, Brock Purdy connected with Jake Tonges for a score. However, those highlights were drowned out by sloppy mistakes and a defense that couldn’t generate enough pressure on Trevor Lawrence. Jacksonville’s opportunistic defense has been forcing takeaways all season. On Sunday, they capitalized again to hand San Francisco a loss that was as much about self-inflicted wounds as it was about the opponent.

Here we'll try to look at and discuss the San Francisco 49ers who are most to blame for Week 4 loss to Jaguars.

Running game still searching for answers

For a Kyle Shanahan-coached team, the lack of a reliable rushing attack is quite alarming. The 49ers haven’t scored a single rushing touchdown through four weeks. The inefficiency on the ground has become a recurring theme. Against Jacksonville, the problems were evident once more: wide receivers whiffing on blocks, linemen miscommunicating assignments, and McCaffrey forced to weave through chaos just to scratch out modest gains.

The numbers tell the story. San Francisco ranked fourth-worst in yards per rush in Week 4. CMC totaled just 49 yards on the ground. Only two carries went for 10-plus yards. Without George Kittle setting the edge, the blocking has crumbled. As such, the offense has lost the rhythm that usually comes from pounding the football effectively.

Pass rush disappears without Bosa

The 49ers’ defense thrives when their pass rush creates chaos. On Sunday, though, Lawrence enjoyed one of the cleanest pockets of his career. He was pressured on just 18.8 percent of his dropbacks. That's the lowest rate for any quarterback in Week 4.

Bryce Huff was the only San Francisco defender to generate multiple pressures. Still, that’s nowhere near enough for a unit built to dominate up front. The absence of Nick Bosa looms like a storm cloud. Anything that Robert Saleh threw out there, Jacksonville’s offensive line handled it with ease. Five total pressures all game just won’t win against playoff-caliber teams. Maybe the Niners need to be aggressive at the trade deadline to add reinforcements.

Kendrick Bourne’s struggles pile up

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With injuries forcing adjustments at wide receiver, Kendrick Bourne has seen more snaps than originally intended. Unfortunately for San Francisco, the results haven’t justified the trust. Bourne was credited with three drops on four targets against Jacksonville. That's an egregious number, especially considering one of those drops came on third down with a clear path to the end zone.

Drops can sometimes be overstated. However, in a game decided by turnovers and missed chances, they mattered. Bourne looks less like a difference-maker and more like a product of Shanahan’s scheme. With Ricky Pearsall sidelined, the options behind him are even thinner. The 49ers might have to consider whether Bourne is helping or hurting more, because right now, his miscues are directly stalling drives.

Brock Purdy needs to be sharper

Purdy’s completed 22 of 38 passes for 309 yards. He also tallied two touchdowns, two interceptions, and a lost fumble. That paints the picture of a roller-coaster outing. Returning from injury, he showed flashes of the rhythm and confidence that usually define his game. That said, the mistakes outweighed the positives. His first interception came off a bobbled ball. Meanwhile, the second was tipped at the line. However, that doesn’t excuse the erratic accuracy and hesitation that popped up at critical moments.

San Francisco needs Purdy to be decisive. Instead, he looked caught between options and missed throws that would have extended drives. Purdy also took sacks when running lanes were available. Against Jacksonville, his decisiveness was absent. With a sore toe lingering and a short turnaround before a divisional clash, the 49ers need their quarterback to bounce back quickly.

Looking ahead

San Francisco 49ers quarterback Brock Purdy (13) stands at the line during the first half against the Jacksonville Jaguars at Levi's Stadium.
Darren Yamashita-Imagn Images

The 49ers’ 26-21 loss to the Jaguars wasn’t about being outclassed. It was about being outplayed in the margins. Four turnovers, a porous running game, a vanishing pass rush, and costly mistakes from both skill players and the quarterback doomed them. Jacksonville is a tough opponent. However, San Francisco handed them opportunity after opportunity and paid the price.

At 3-1, the season is far from lost, but the concerns are real. If the 49ers don’t fix their running game, find answers in the pass rush, and get sharper play from both receivers and Purdy, more losses like this one could follow. In a competitive NFC, they can’t afford that.