Marshawn Lynch had two seasons left on his contract when he was acquired for a pair of fifth-round picks in 2010. He just signed a four-year extension that will keep him in Seattle for most of his productive years, making him one of their better trade acquisitions.
There are a few hurdles to high-profile trades.
Perhaps the biggest is that teams can face difficult salary cap hits. Any pro-rated portion of signing bonuses hit the team's cap the year in which a player is dealt, or spread across two years if dealt after June 1. The dead weight for elite players with large bonuses makes it difficult, particularly in the early years of a contract.
Still, players like Carson Palmer and Richard Seymour have been dealt for high draft picks.
There are a few accessible players on the horizon that would make a solid impact on the Seahawks' roster.