(Seattle's run D is only average)
Curious to know which metric you are using to make this statement. Or perhaps not a stat, but a general feeling?
I ask not to be contrarian, but due to a feeling. Stats would show us that Seattle has a much better than average run defense, but I teach advanced placement statistics for a living and I'm always on the lookout for dirty stats that absolutely wreck the notion of "independence". Not all rushing attempts are the same. Not all run stops are the same. Not all opportunities are the same. The stats are being complied behind different offense lines and against different defense schemes and personnel.
My gut tells me Seattle might struggle to stop the run today. We shall see.