While there is yet to be a formal announcement there is a strong indicator that Will Bates has joined Seattle Sounders FC. He tweeted it. Bates was drafted in this year's Supplemental Draft and was recovering from an injury.
Today, I am proud and excited to say that I have officially signed with the Seattle Sounders... Thanks to all for the love and support!— Will Bates (@WillBates10) April 18, 2013
That would put the club at thirty players barring another move. Another move is possible, just based off of what Sigi Schmid said in practice today about Josue Martinez' time with the team.
"We liked him when he played with Saprissa," Schmid told the media. "He played against us with Saprissa when we were in the Champions League. Philadelphia had him, New York had him, and they let him go, so we felt this was a good opportunity to look at him because we also have two reserve games—one we just played and we have one coming up on Tuesday—so we felt we could give him a good look and make a decision at that point."
But there's also no player on that would make sense for one of the Injured Lists. Players could still be cut, but with Reserves and Open Cup and a crowded May that makes less sense right now. The team could buy time by having Martinez hang out with them and play a third Reserve match (that was the limit in 2012).
Another option would be to find a long(ish) term loan for a player to another team. If that team picks up the contract the player's rights would still be held by Seattle, but the roster spot would open. At least the rules appear that way, per moves like Alvaro's and Fredy's and others this season. Players like Duran, Fairclough, Carrasco, Ford and Remick all have lower salaries and are unlikely to get time in the near term.
One thing is certain. If Seattle needs roster space to sign a player they will find it.