Ex-Crystal Palace star Smith fails to agree Real Zaragoza terms
Smith was trialling with Real after being released by Sporting Kansas City.
Smith's advisor, Ryan Badu, told skysports.com: "Everything about the club was great and Ryan was keen to join them, but we simply couldn't agree on certain things on the playing side.
"We haven't got a bad word to say about the club and everybody connected with it, but it was quite time consuming and at this stage of the season time is of the essence.
"It wasn't an easy decision to leave Spain, and Zaragoza were keen to keep Ryan on, but we have other options available and hopefully something will happen with one of those very soon."