The San Francisco 49ers are set to do battle with their NFC West rival Seattle Seahawks on Sunday at Lumen Field. The 49ers are sporting a 4-0 record, with Seattle coming in at 3-1. The Seahawks won two of the three matchups last season, including the season finale at Levi’s and the divisional round before finishing the job against the New England Patriots at Levi’s Stadium. After celebrating twice in the 49ers building, the team has some work to do to inflict the same pain on their rivals.
So, how
do the 49ers do that? In the final two matchups, the 49ers offense had to scratch and claw for every inch. Yes, the offense was depleted, but Seattle’s defense was incredible. After spending an offseason looking to add separators at the receiver position, the 49ers aren’t at the level of threat they would like to be, but are far more equipped to handle Seattle’s defense, especially with Brock Purdy’s play in 2026.
Here are three things to watch for Sunday:
Beating Seattle’s pass rush
The 49ers offensive line has kept Purdy clean through four weeks. That’s a feat not easily dismissed regardless of the opponents, but they will face their biggest test of the season against a Seattle pass rush that ranks number one in pass rush win rate, according to ESPN, and sits at the bottom of the league in blitz rate. Straight drop-back and obvious passing situations aren’t where the 49ers want to live against Seattle.
Through four weeks, Seattle’s defense is 2nd in EPA/play allowed but is 19th in EPA/play allowed on throws happening quicker than 2.5 seconds, according to SumerSports. The Seahawks are also 28th in EPA/play allowed on short throws. The quick game will need to be on display; look for the 49ers to target Deebo Samuel on these plays, but Mike Evans will need to get past the sticks quickly for Purdy.
Breaking through against Mike MacDonald
Purdy and Shanahan have beaten MacDonald-led defenses before. However, that was before the defense gelled and the organization got its personnel together. According to SumerSports, in the first three meetings between Mike Macdonald and Brock Purdy, Purdy had 87th, 65th, and 87th percentile performances by EPA/dropback. In the last two, Macdonald’s swarming Seahawks held Purdy to a 10th and 5th-percentile EPA/dropback.
For those keeping score at home, the first three performances are good. The last two aren’t, and the 49ers offense hasn’t scored a touchdown against Seattle through eight quarters. The deck is set more fairly for Purdy, but Shanahan and Purdy have their work cut out for them on Sunday.
The 49ers offense against base, nickel, and light boxes
So far, the 49ers have torched base defenses to the tune of a league-leading 0.29 EPA and have faced base defenses at a league-high rate of 48.6%. Against nickel, the 49ers have faced the second-to-last percentage of 41.4%, but lead the league with a 0.24 EPA. While against light boxes, the 49ers lead the league with 0.52 EPA, but have faced light boxes at the lowest rate in the NFL at 29.7%.
Seattle under MacDonald hasn’t been known to play much base defense, and the same is true in 2026. With a 15.5% base percentage, Seattle ranks 29th in the NFL, but sports the third-best EPA allowed at -0.37. The jump from base to nickel is striking, with Seattle in nickel for 68.2% of their snaps, which is tenth, and has allowed the third-best EPA at -0.23.
Where things get interesting is that Seattle defends the run well without loading the box, and the proof is in the numbers. Their light box percentage sits at 51.4%, the eighth-highest in the NFL, and they allow the fifth-best EPA at -0.16.
Can the 49ers punish their light boxes with throws in the middle and running the football? That is where the game will be decided.
