In winning the U.S. Open Cup tournament, Sounders FC qualified for the preliminary round of the 2010–11 CONCACAF Champions League.

On November 22, 2010, Seattle made a trade with the Colorado Rapids for defenders Julien Baudet of France and Danny Earls of the Republic of Ireland for Peter Vagenas.

The draft took place on November 24, 2010, when both the Portland Timbers and Vancouver Whitecaps FC selected ten players from the Major League Soccer teams, including Sanna Nyassi (who was later traded to Colorado) and Nathan Sturgis (who was later traded to Toronto) from Seattle Sounders FC.

[4] On December 9, 2010, Swedish club, BK Häcken reported that midfielder, Erik Friberg completed a three-year deal with the Seattle Sounders FC, bringing him over to the team.

On December 15, 2010, the Sounders selected Chris Seitz of the Philadelphia Union in the 2010 MLS Re-Entry Draft.

[5] The goalkeeper was later traded to FC Dallas for a fourth round pick of the 2012 MLS SuperDraft.

[7] The Sounders opened up the 2011 regular season against the defending Supporters' Shield titleholders, Los Angeles Galaxy at Qwest Field.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Each club in Major League Soccer is allocated 8 international roster spots, which can be traded.