Usually, the Madden curse sidelines a player for the whole season (or most of it). This isn't "supposed" to keep Shaun out for too long, and with a bye week in there, he'll miss one less game. You don't like to lose the league MVP from the team, but I think the Seahawks will do okay without him for a short while. The passing game is now lethal, and if Mo Morris can just break a few 5-10 yard runs per game, it will keep opposing defenses honest. The 'Hawks defense has also been incredible so far, and that has really been the key in the first three games.
If the Seahawks really are one of the top teams in the league, they'll find a way. However, if they're like every other Seattle team in recorded history, they'll fold faster than a hobo playing cards...