To take Seau's place on the active roster, the Dolphins promoted defensive end Ronald Flemons from the practice squad for the second time this year and running back Vick King was re-signed to the practice squad.
On Wednesday, Seau spoke to his teammates in the locker room and also talked with reporters before leaving for California, where he will be rehabilitating.
"Will I play again? Of course I will play again," Seau said. "I'm going to say that now, but it can change tomorrow. Obviously, it's an injury. I'm on IR and things are going to have to be on hold. That's the worst part of this."
A serious injury is something new to Seau, who had never missed more than three games in his first 14 seasons in the league.
But it's not just the nature of the injury that have people wondering this will be the end of Seau's career. There's also the age factor; Seau will turn 36 next January.
"Assessing my situation after the surgery is definitely going to be something that I need to do," he said. "Obviously I'm walking away from the game, which I always wanted to towards the end, but I never thought I would be walking away with a sling and that doesn't sit well with me. As far as what I may do in the future, if you ask me today, I'm going to say yes, but it will be assessed after everything is said and done."
Based on his play this season, Seau certainly has a lot of good football left in him. He is currently second on the team with 68 tackles, to go along with a sack and four tackles for loss.
One issue that could prevent a return to the Dolphins is that Seau was scheduled to make $3 million in base salary in 2005 and he also is scheduled to get a roster bonus early in the offseason.
Any way it shakes out, this was a sad day for Seau.
"I feel like I'm in detention," he said. "I can't go out to recess, I have to look and watch everybody else play. It's not a good feeling.
"I don't know how I'm going to handle it. I will probably sit in first class on American Airlines today and probably sob all the way back home. I don't know. There is so much going on personally that I probably haven't even hit the ... I'm just on the surface of my emotions right now."