Well this is easy.
Receiving/Move tight end
Starter: John Carlson
Backup: Cameron Morrah
John Carlson is Zach Miller. Zach Miller is John Carlson. You would be hard pressed to find a better one-to-one comparison. High 4.8 speed? Check. 6'5" 255? Check. Route-running machines? Check. Saddled with terrible quarterbacks that undermine their production? Check and check. In what can only be called the Curse of Tim Ruskell, Carlson is actually older than Miller. And that's bad, because tight ends are not known for their longevity.
Carlson suffered a huge dip in his production this season. It wasn't because of an apparent drop in talent or skills, but a mix of factors. He became Matt Hasselbeck's favorite target for throwaways, much to the detriment of his advanced stats. Carlson was targeted 58 times. STATS Inc. lists eight as overthrown, two as underthrown, two as thrown wide, two thrown away intentionally, one batted down at the line of scrimmage and four dropped. So, of the 27 passes thrown to Carlson that He couldn't complete, STATS Inc. lists 15 as uncatachable, four as dropped and another five were "defensed." We can blame Him for the latter two categories, anyway.
Carlson also became the factotum of the offense: playing fullback, splitting wide, blocking way too much, and doing everything but trick plays and end arounds.
It was a bad season from a fantasy perspective, and led to questions about What happened? Where is He? And the inevitable, Is Carlson overrated? But JC was better as a blocker, precise as ever as a route runner, healthy as usual and still valuable, if not a Playmaker or Game Changer or Playgamemakechanger.
Morrah is the guy pressing him for time, and an intriguing replacement if and when the time comes. Morrah is younger, faster, more athletic and has a higher ceiling. It's a nice dilemma to have, and hopefully Cable and Bevell find ways to use both.
Blocking Tight End
Starter: Chris Baker
Backup: Anthony McCoy
Baker is the lunch pail guy. He only does a few things, but does those things well. McCoy is the better athlete, the better prospect (obviously) and potentially the best overall talent among Seattle's tight ends. A few years from now, McCoy might become a very valuable player, and he might be out of the league. If he had shown anything, even a few nice plays in the preseason, it would have given us reason to think he is ready to tap into that talent. But he didn't. He wasn't active and he didn't contribute. Which is okay, because Baker is signed through next season and steady.
Put simply, Seattle doesn't need talent at tight end.