The Seahawks released Jackson on Thursday, Curtis Crabtree of Fox 13 Seattle reports.
A transaction that made sense for the Seahawks, the team decided to part ways with Jackson likely due to a combination of his age, lingering knee concerns and his hefty salary cap number ($11.3 million) for this coming season. The 335-pounder started in 31 games for Seattle across the previous two campaigns, and he'll now look elsewhere to continue his playing career.