San Francisco 49ers vs Seattle Seahawks Prediction

Seattle should edge San Francisco on Sunday by about two points, which makes this a close game with a slight lean to the home team. The 49ers are 4-0 and have the best passing offense in the league so far, but their defense is expected to be without Nick Bosa and two other contributors, and they are walking into the loudest building they have seen this season. Seattle's defense is the best unit San Francisco has faced. This is a forecast, not an official play.

How both teams got here

San Francisco is 4-0 under Kyle Shanahan. The 49ers beat the Rams 27-7 in Melbourne, beat Miami 35-13 at home, held off Arizona 36-30 at home and beat Denver 24-14 at home. The last two were tighter than the first two. Arizona was within two points with 1:36 left, and the Denver game was 17-14 until a 56-yard Kittle screen with 2:23 to play.

Seattle is 3-1 under Mike Macdonald. The Seahawks beat New England 13-10 at home, won 31-7 at Arizona with Drew Lock starting at quarterback, lost 33-31 at Washington and beat the Chargers 30-23 at home after leading 27-6. Both teams come in on normal rest, and this is San Francisco's first true road game in a hostile outdoor stadium.

San Francisco's case

The 49ers have been the best passing team in football through four weeks. By expected points added (EPA), a measure of how much each play helps an offense score, San Francisco ranks first in the league per dropback. The protection is the reason. The 49ers have not allowed a sack in four games and rank first in the rate of sacks plus quarterback hits allowed, at 9 percent of dropbacks.

Brock Purdy has taken full advantage. Over his last three games he has thrown 11 touchdown passes with no interceptions and no sacks taken. Kittle, Samuel and McCaffrey are healthy, Trent Williams is back, and the offense has scored touchdowns on 10 of its 11 red zone trips over the last three weeks.

There are soft spots. The run game ranks 15th, and the receiver room is thin, with Kirk, Robinson, Pearsall and Stribling on injured reserve and Mike Evans playing through fractured ribs. The defense allows only 16 points a game but ranks 18th against the pass by EPA and 26th in pass rush, and Arizona converted 9 of 18 third downs against it over 80 plays.

Seattle's case

Defense is Seattle's identity. The Seahawks rank fourth against the pass and third against the run by EPA allowed, fourth in pass rush with sacks or hits on 28 percent of dropbacks, and first in the league in passing yards allowed at 144.8 per game. Ernest Jones, Drake Thomas, Witherspoon and Emmanwori are all playing well.

The offense is less settled. The passing game ranks 10th and runs through Smith-Njigba, but the run game ranks 28th and the pass protection ranks 20th. Sam Darnold has thrown an interception in both games since he returned to the lineup. Seattle scored 13 points at home against New England without a red zone touchdown, turned the ball over three times in the loss at Washington, and had 14 penalties against the Chargers in a game that swung on three Los Angeles turnovers.

Seattle wins with defense, takeaways and field position, and it loses when it gives the ball away.

Injuries and lineup news

Both starting quarterbacks are set. Brock Purdy starts for San Francisco with Kurtis Rourke behind him, and Sam Darnold starts for Seattle and was not on the first injury report of the week.

The 49ers' defense carries the bigger injury load. Nick Bosa (knee and calf) did not practice to open the week and Shanahan has said he does not expect him to play, which would put rotation player Ogbo Okoronkwo in his spot. Starting safety Marques Sigle has a high ankle sprain and is out, with Malik Mustapha next up. Rotation defensive tackle James Thompson Jr. is doubtful. On offense, fullback Kyle Juszczyk (knee) is out, and San Francisco has no like-for-like backup for him. Cornerback Upton Stout (shoulder) sat out the first practice but is expected to play. Mykel Williams, who tore an ACL last November and has been on the physically unable to perform list, has returned to limited practice, but he has not played this season and whether he is activated for this game is unconfirmed.

Seattle's list is lighter on defense. Leonard Williams (ankle) was limited, and Macdonald expects him to play. The backfield is the issue. Zach Charbonnet remains on the physically unable to perform list and Jadarian Price is on injured reserve, so Emanuel Wilson carries the load while George Holani (ribs) is limited. Starting right guard Anthony Bradford is on injured reserve, and rotation guard Beau Stephens (knee) was limited.

Weather should not matter. The forecast for Lumen Field calls for about 59 degrees, a light 7 mph wind and no rain.

How the matchup sets up

Our interpretation is that one matchup is the game: San Francisco's unsacked protection and top passing attack against Seattle's top-five pass rush and coverage, in the Lumen Field noise. That is strength against strength, and we do not think either side has a clear advantage there. It is the main reason our lean is small.

The second matchup tilts toward Seattle. The 49ers' pass rush already ranked 26th before losing Bosa, and the secondary is down a starting safety. Arizona and Denver both sustained drives against this defense when it was healthier. That gives Seattle's passing game its opening.

What keeps that edge from being large is Seattle's own offense. A run game that ranks 28th is down to its third option at running back and missing its starting right guard, and the protection has been average. The one common opponent points the same way, though softly: Seattle won by 24 at Arizona with its backup quarterback, and San Francisco beat the Cardinals by six at home.

Turnovers are the swing factor. Seattle's two home wins leaned on six takeaways, and San Francisco has not turned the ball over in three games. Neither is a trait we expect to hold at that level. Rest, weather and coaching do not separate these teams. Add it up and we have Seattle by about two.

The key risk

The biggest threat to this forecast is the 49ers' passing game continuing to do what it has done everywhere else. Purdy has been close to flawless for three weeks, and Seattle's offense has been uneven enough that it may not be able to keep up if its defense does not get pressure. If San Francisco's protection holds up in the Lumen Field noise, the 49ers win this game outright.

The injury picture could also shift. Our lean rests largely on San Francisco's defensive absences, so the activation of Mykel Williams or a surprise return by Bosa would shrink that edge. The final game statuses for Leonard Williams, Mike Evans and Upton Stout are worth checking before kickoff as well.

Who's in and who's out

Availability as of October 7 at 9:27 PM ET. Each player's role is checked against the snaps he actually played, not just the depth chart, so a starter and a backup on the same injury report are not treated alike. This updates automatically as the injury report changes.

San Francisco 49ers

Marques Sigle, safety, out: a verified starter. Snap share over the last three games: 100 percent, 83 percent, 68 percent. Next up on the depth chart: Malik Mustapha, who has been playing a regular rotation share.

Nick Bosa, defensive end, doubtful: a verified starter. Snap share over the last three games: 68 percent, did not play, did not play. Next up on the depth chart: Ogbo Okoronkwo, who has been playing a regular rotation share.

Kyle Juszczyk, fullback, out: listed as a starter on the depth chart, but his recent snaps say he has been in a reduced role. Snap share over the last three games: 44 percent, 56 percent, 41 percent.

Mike Evans, wide receiver, questionable: listed as a starter on the depth chart, but his recent snaps say he has been in a reduced role. Snap share over the last three games: 54 percent, 33 percent, 59 percent. Next up on the depth chart: Jacob Cowing, who has been playing a regular rotation share.

Upton Stout, cornerback, questionable: listed as a starter on the depth chart, but his recent snaps say he has been in a reduced role. Snap share over the last three games: 58 percent, 63 percent, 55 percent.

James Thompson Jr., defensive tackle, doubtful: a rotation player. Snap share over the last three games: 36 percent, did not play, did not play. Next up on the depth chart: Alfred Collins, who has not played a snap this season.

Kaelon Black, running back, questionable: a rotation player. Snap share over the last three games: 33 percent, 15 percent, 26 percent. Next up on the depth chart: Jordan James, who has seen little action.

Also listed, all reserves who rarely play: Christian Kirk.

Seattle Seahawks

Leonard Williams, defensive tackle, questionable: a verified starter. Snap share over the last three games: 70 percent, 81 percent, 58 percent. Next up on the depth chart: Mike Morris, who has seen little action.

Ty Okada, safety, on the practice report (hamstring): listed as a starter on the depth chart, but his recent snaps say he has been in a reduced role. Next up on the depth chart: Bud Clark, who has not played a snap this season.

Beau Stephens, guard, questionable: a rotation player. Snap share over the last three games: 39 percent, 40 percent, 42 percent. Next up on the depth chart: Mason Richman, who has not played a snap this season.

George Holani, running back, questionable: a rotation player. Snap share over the last three games: 26 percent, 36 percent, 37 percent. Next up on the depth chart: Velus Jones Jr., who has seen little action.

Nehemiah Pritchett, cornerback, questionable: a rotation player. Snap share over the last three games: 76 percent, 52 percent, 28 percent. Next up on the depth chart: Avery Smith, who has seen little action.

Also listed, all reserves who rarely play: Tyrice Knight, Irv Charles, Chazz Surratt, Zach Charbonnet.

The verdict

We expect Seattle to win a close division game by about two points, driven by a 49ers defense that is short on pass rush and a Seahawks defense good enough to test the league's best protection. San Francisco is fully capable of winning if Purdy stays clean, and late injury news on Bosa could narrow the gap further. This is a forecast, not an official play.