Seahawks WRs Sidney Rice (18) and Doug Baldwin combined for 155 yards against the Patriots. Yards could be a bit tougher to come by going against a San Francisco pass defense that ranks second in the NFL. (US Presswire)

Seahawks at 49ers -- Week 7

Where: Candlestick Park, San Francisco (grass, outdoors) 

When: Thursday, 8:20 p.m. ET (NFL Network)

Spread: 49ers by 7

Forecast: High-70s projected at kickoff, down to mid-60s after sunset. 

Records: Seahawks (Overall: 4-2, NFC West: 0-2); 49ers (Overall: 4-2, NFC West: 0-0)

Past results: Two most recent meetings -- Dec. 24, 2011: 49ers 19, Seahawks 17; Sept. 11, 2011: 49ers 33, Seahawks 17. Series record: Series tied 13-13.

What matters: NFC West. Thursday night's game in San Francisco isn't a must-win for the Seahawks, but it's as close to a must-win as a 4-2 team can have. A loss to the 49ers would drop the Seahawks to 0-3 in the division just seven weeks into the season. With the NFC West so tight, a win here would be big because the Seahawks will most likely need all tiebreaking advantages they can get come the end of the regular season. 

Who matters: The Seattle defense. Under Jim Harbaugh, the 49ers have been impressive after losses. In four regular-season losses before Sunday, San Francisco outscored its opponents 93-11 in its following game, meaning opponents are only averaging 2.75 points per game. If the Seahawks' offense can't score, it will be up to the defense to keep them in the game.  

Key matchups: Seahawks defensive line vs. 49ers offensive line. If the Seahawks want to have a chance to upset the 49ers, the defense is going to have to do one key thing: stop the league's top-ranked running game (176.8 ypg). In San Francisco's four wins, the 49ers have averaged 223 rushing yards. But in the Niners' two losses, they've averaged only 84.5 yards. The good news for Seattle is that stopping the run is the defense's strength. The Seahawks' run defense is ranked second in the NFL, and no team has run for more than 87 yards on them this year. 

Injuries of note: Starting G John Moffitt (knee) has been ruled out for Thursday. This will be the fourth time this season that Moffitt has been inactive. He was inactive in Weeks 1, 4 and 5. Backup CB Byron Maxwell (hamstring) is the only other Seattle injury of note, and he's listed as doubtful for Thursday's game. 

Inside stuff: The last time the Seahawks and 49ers met in a primetime game was in November 2007. On Monday Night Football, Seattle pitched a 24-0 shutout against the Alex Smith-led 49ers. The last time the teams met on a Thursday was December 2006, when San Francisco beat the playoff-bound Seahawks 24-14. 

Connections: Thursday will mark the third time Pete Carroll and Jim Harbaugh have faced off in the NFL, but they also faced each other three times in college with Harbaugh's Stanford Cardinal holding a 2-1 edge over Carroll's USC Trojans. Stanford's 24-23 win over Carroll's No. 2 USC team is largely regarded as one of the biggest upsets in college football history. This week will also be the second in a row where Carroll has faced a team he used to coach for. The Seahawks' third-year coach was the defensive coordinator in San Francisco from 1995-96. The most notable connection belongs to Seahawks LB coach Ken Norton Jr., who played for the 49ers from 1994-2000. 

Stat you should know: The two highest single-game rushing totals in 49ers' history were accomplished by Frank Gore, and they both came against the Seahawks. Gore ran for 207 yards against Seattle in 2009 and 212 in 2006. But in his last four games against the Seahawks, Gore has only averaged 51.3 ypg. 

Record watch: A win over the 49ers on Thursday would give Seattle its first 5-2 start under Carroll. The Seahawks haven't started a season 5-2 since their 2005 Super Bowl season.  

Looking ahead: The Seahawks will rack up a few more frequent-flier miles in Week 8 when they travel to Detroit to complete a string of four road games in five weeks. The Seahawks will have traveled 6,615 miles in the four road games, which is more than the Green Bay Packers will travel the entire season (5,774). 

Prediction: Seahawks 16, 49ers 13

For more up-to-the-minute news and analysis from Seahawks blogger John Breech follow @JohnBreech and @CBSSeahawks.