The Seahawks have waived/injured Anthony McCoy. The fourth-year tight end tore his achilles tendon last week and is very unlikely to play in 2013 as he faces a probable six-to-nine month rehabilitation. McCoy is now subject to waivers and if no team claims him, he'll revert to Seattle's reserve injured list.
Essentially, the Seahawks don't see McCoy as a contributor this season due to the injury, and likely felt it was an acceptable risk that another team may claim the 2014 unrestricted free agent. If another team does claim McCoy, they'll be paying him his $656k salary in the hopes that he is able to return to full health and get himself in physical condition to play before the 2013 season is over - and that's a bit of a stretch in the first place. Regardless of whether or not McCoy can indeed come back in 2013, he'll be a free agent anyway when the 2014 season rolls around.
Taking McCoy's spot on the active 90-man roster is T Jake Bscherer. We talked about that signing last week, so read about that here.