Montreal Impact in last week's MLS Expansion Draft and immediately traded to Chivas.
Riley has been a regular starter at Seattle for the past three seasons and has done a load of work off-field with a number of charities and will be sorely missed by all involved at the Sounders.
His statement speaks of how much he loved his time in Seattle and that he is saddened to be leaving the club he has given so much for the last three years of his life.
"Sadly, it is with a heavy heart that I realize my departure from the Seattle Sounders and this blue-skied city. The overflow of kind messages I have received across all boards over the last few days has been overwhelming. Undoubtedly, this support is even more encouraging and gratifying because it pertains to the totality of my efforts.
"I can honestly say, I gave my heart and soul to this city for three extraordinary years. Even more so, I redeemed my days with great vigor and compassion off the field in a community I have grown to love.
"I took full advantage of my time here and despite the nature of professional sports, I distinctly chose to integrate into the city. This is why, I think, I have been supported and received so well. I am just a regular guy that has been blessed to make a living doing something I absolutely love. I was engaged, committed, and involved. An extraordinary energy that was continually reciprocated by all my fans and community partners.
"I never worried about circumstances out of my control but instead, I concentrated on taking advantage and utilizing the opportunities I was given.
"Certainly, I would like to thank everyone involved with my success, which includes all of the SSFC fans and supporters, especially the ECS and Gorilla FC. I would also like to sincerely thank the Seattle Sounders club, front office/support staff, coaches, and trainers. Thank you to my marketing manager Rich Martin. In addition, I would like to thank all of my community partners, Boys and Girls Club, Special Olympics, America Scores, Susan G. Komen, Ronald McDonald House, Children's Hospital, Gilda's Club, Union Gospel Mission, Hope Place, Sadie Lynn Rainford, Korean American Coalition, Emerald City Supporters, Gorilla FC and Mars Hill Church.
"Most importantly, I would like to thank my teammates. It was an absolute pleasure suiting up with you gentlemen and going into battle these last three seasons together. I have forged bonds, friendships, and memories within this city that will last a life time.
"I am eager to turn the next chapter and embrace the future opportunities that lie before me."