The 49ers offense struggled badly in their first matchup with the Seahawks. They were without a couple key players, the offensive line struggled, and Jimmy Garoppolo had his worst game of the year.
Another showing like the one they had in Week 10 could mean a runaway win for the Seahawks. These three players will be big difference-makers for San Francisco in their attempt to avoid another letdown against Seattle:
QB Jimmy Garoppolo

Garoppolo was bad against Seattle in their first meeting, and could’ve been worse had the Seahawks defense not dropped a couple interceptions. It wasn’t all his fault, but now he steps into perhaps the most hostile environment in the NFL at CenturyLink Field. We’ve seen Garoppolo play well in the Superdome – another raucous road environment – but how he responds in his first trip to Seattle will be the biggest key for the 49ers’ offense.
LT Joe Staley

Part of the reason Garoppolo struggled against Seattle in their first meeting was Staley’s inability to protect his blind side. Staley, in his first game back off a broken fibula, had a hard time staying in front of Seahawks defensive end Jadeveon Clowney. The 49ers couldn’t get much going on offense with Clowney living in the backfield. This is a matchup Staley will see plenty again Sunday. If he’s better, the 49ers’ entire offense will improve.
TE George Kittle

The 49ers didn’t have their Pro Bowl tight end in Week 10 as he worked through knee and ankle injuries, but his absence was apparent in all facets of the offense. Seattle isn’t particularly good at covering tight ends, and Kittle gives the 49ers’ offense a wrinkle of deception they don’t have when he’s off the field. In a hostile environment, Garoppolo will need pass catchers he trusts, and there’s not a better playmaking security blanket than Kittle. He could be in for a big night Sunday.