Look, I greatly respect the coaching staff of the 49ers especially Kyle Shanahan and defensive coordinator Robert Saleh. But the 49ers are out of gas both physically and mentally. It's difficult to keep a team together that misses the playoffs after reaching the Super Bowl the previous season and has the longest injury list in the league. San Francisco is 2-6 in its last eight games with every loss during this span coming by at least eight points. 
Seattle is coming on especially its defense, which has surrendered the fewest points in the league during the last seven weeks. The Seahawks draw third-string QB C.J. Beathard, who is 2-14 in his 16 NFL appearances. He has a career mark of 17 touchdowns and 23 turnovers while being sacked 43 times. Seattle has the most sacks in the NFL since Week 8. Superstar safety Jamal Adams already has set a single season sack mark for a safety. 
Aside from tight end George Kittle, Beathard doesn't have his top receiving weapons with Brandon Aiyuk and Deebo Samuel ruled out. San Francisco is missing some of its top offensive linemen, too, including left tackle Trent Williams. The 49ers' pop-gun, conservative ground-based attack isn't going to produce many points and will be helpless if the Seahawks jump to a big lead, which I anticipate. Seattle has held its past five foes to an average of 12.2 points. 
Defensively the 49ers not only are missing multiple linemen - as they have all season - but have a cluster injury problem in their secondary. Cornerbacks K'Waun Williams and spiritual leader and warrior Richard Sherman are out. Emmanuel Mosely is questionable. Russell Wilson fired 4 TD passes in the Seahawks' 37-27 Week 8 victory against San Francisco.
The Seahawks still have an outside shot at earning the NFC's top seed. So they aren't going to lack incentive.