Locks - Doug Baldwin, Jermaine Kearse, Tyler Lockett
Near-Lock - Paul Richardson
Bubble Leaders: Kenny Lawler, Kasen Williams, Kevin Smith
Bubble Busters: Doug McNeil, Deshon Foxx, Antwan Goodley, Tanner McEvoy, Tyler Slavin
The Seahawks kept five receivers last season, not including brief appearances by Richardson and Ricardo Lockette. Let's also keep in mind that Smith was targeted five times all year and Williams was targeted once. The way the offense has been setup means that barring injury, Seattle will already be fighting to find opportunities for Richardson, should he stay healthy and make the team. (And if he's healthy, you would think there's very little chance he doesn't make the team.)
So a lot of people will probably be quick to comment that Lawler is going to surprise people this year or that McNeil is underrated or a bunch of other things that rhyme with "blah blah blah" but it's just a matter of logistics: The Seahawks don't have room for anyone else to be catching passes this year other than their top four receivers, their elite tight end, and a rookie third round running back named C.J. Prosise who could become Russell Wilson's favorite underneath target.
An educated guess: Smith is the number five receiver and they stash Williams, McNeil on the practice squad, while Lawler gets picked up off waivers.