Bobby Engram cracked a bone in his shoulder and will miss 6-8 weeks, which probably translates to the first four games of the season (the Seahawks have a bye in Week 4). That isn't a major concern and might not even result in an extra receiver on the roster.
The Seahawks will typically have 4 active receivers on game days. The concern will be the health of Logan Payne and Courtney Taylor as August 30th approaches. As long as they are ready to play, then the Week 1 actives will be...
Nate Burleson, Ben Obomanu, Courtney Taylor, Logan Payne
Branch will miss the first couple of games, Bobby will miss the first month or so. Seneca Wallace would be available in an emergency situation, and Jordan Kent and Michael Bumpus can beMarcus Tubbs called up from the practice squad.
The Marcus Tubbs release shouldn't be a surprise. His career has been unofficially over for nearly a full year. The battle for the final DT spot is between Howard Green, Larry Tripplett, and Chris Cooper. Green was on the team last year, isn't sidelined with an injury, and has been playing well in practice and the preseason. He has the clear lead in that race.