Besiktas signing Simao makes emotional Atletico Madrid farewell
Simao joined Atletico in 2007 for 20 million euros from Benfica and believes he has given his all in the Spanish capital.
He said: "I don't think I have defrauded anyone. It is difficult for me, I can hardly speak because since I came to Atletico I have grown and become a better professional.
"When I arrived I said I would do my best to win a title and I eventually ended up with two in Europe (the Europa League and the European Super Cup).
"I have to thank the fans, the support they have given me has been spectacular. I will continue to follow Atletico as a fan myself."
Atletico president Don Enrique Cerezo hailed Simao's contribution over the past three-and-a-half years.
"We are here today to say farewell to a great player who has had so much success with Atletico Madrid," he said.
"And we are here, above all else, to say farewell to a great person who we have all been privileged to know over the past few years."