49ers historic collapse against Seahawks exposes Kyle Shanahan's biggest playoff weakness

The San Francisco 49ers walked off the field after a 13-3 loss to the Seattle Seahawks, having produced their most anemic offensive performance since Kyle Shanahan took over in 2017.

Three total points told only part of the story. San Francisco failed to control tempo, protect its quarterback, or impose a running identity that had defined its late-season surge.

Seattle dictated the game by monopolizing possession for nearly 40 of the 60 minutes, forcing the 49ers into a reactive posture.

Brock Purdy spent much of the night under siege as the offensive line repeatedly collapsed, culminating in a heavy hit on the final snap. The lack of rhythm was exacerbated by limited success on play-action plays and questionable clock management during key stretches.

The run game never materialized. Christian McCaffrey logged just eight carries, a startling figure for an offense built around balance. San Francisco finished with only one rushing first down, a rarity that has occurred just three times in nine seasons under Shanahan.

Despite the loss, the 49ers still reached the postseason at 12-5 after navigating a year riddled with injuries. Defensive leaders Nick Bosa and Fred Warner missed most of the season, and Purdy was sidelined for eight games.

Shanahan acknowledged the tougher road ahead, saying, “I don’t think we cared who we played,” while emphasizing the challenge of winning three straight road games.

The defeat, however, stripped the team of a first-round bye and exposed vulnerabilities at the worst possible time.

Seahawks loss magnifies tactical flaws as 49ers shift focus to Eagles

San Francisco entered the regular-season finale riding a six-game winning streak and boasting the league’s most productive offense since Purdy returned in Week 11.

That momentum vanished against a Seahawks defense that forced four punts, double the total from the team’s three December games combined. Receivers struggled to generate yards after the catch, and Purdy rarely had time to operate cleanly.

The defensive side offered little relief. Seattle gashed the 49ers for a season-high 180 rushing yards and consistently extended drives.

According to Pro Football Focus, San Francisco missed 18 tackles, with linebacker Tatum Bethune accounting for five and safety Malik Mustapha adding three.

Shanahan later said, “18 missed tackles were way too much.”

Special teams provided the lone bright spot. Eddy Pineiro connected on a 48-yard field goal, finishing the season 28-for-29, with his only miss coming from 64 yards in Week 16. Opponent kicking woes also continued to favor San Francisco, as Seahawks kickers missed twice, part of a league-high 11 misses by 49ers opponents this season.

The loss sends the 49ers on the road to face the Philadelphia Eagles in the wild-card round. Kyle Juszczyk summed up the mindset simply: “Let’s do it the hard way.”