The Ecuador international joined City from Basel in January 2008, but has failed to make an impact at the club.
“For me it is difficult to get in the starting XI at City and the opportunity to go to Sporting would be good,” he said.
“I don’t think it would be a problem to adapt to life in Portugal and the possibility to play in the Champions League appeals to me.
“The coach at Sporting (Paulo Bento) has asked about my services and it is nice to feel wanted as a player.”
