Nasri appeared as a substitute against West Ham at the weekend and Guardiola had said he would remain in his thoughts if he stayed.
He told Sevilla's website: "Guardiola, until the last moment, tried to make me stay but I was clear I wanted to leave and go to a place where I could give my best level. I was looking for a family club and in Sevilla I have found just that, but until the last moment I haven't been able to leave."
Nasri is confident he can soon get up to speed at the Ramon Sanchez Pizjuan Stadium.
"I'm fine, because I played last weekend with Manchester City," he said. "I am very excited and I hope to do my best."