The Spaniard played just two games for Villa during his time in England.
Crespo made just two appearances for Villa in his first season in England.
The Greek club are currently in talks with Villa over a deal for the 29-year-old Spaniard.
The defender has made just one Premier League appearance for the Villains.
Jose Angel Crespo has only made two appearances for Aston Villa so far this season.
Jose Angel Crespo has left Aston Villa for Rayo Vallecano.
The two Aston Villa players have had contrasting seasons to date.
Jose Angel Crespo has made just two appearances for Aston Villa since joining in the summer transfer window.
Aston Villa could lose one of their summer signings this month.
The Spanish midfielder has started each of new boss Remi Garde's first three games in charge after struggling to earn a regular spot in Tim Sherwood's side.