Enrique made 99 appearances for the Reds in five years having joined the club from Newcastle in 2011 for a fee of £7million.
He was initially a popular figure ay Anfield and was part of the side which won the League Cup in 2012.
But he barely featured in recent seasons and did not see a single minute of action in the Premier League last season.
Now he has opted to return to his homeland with Zaragoza, signing a two-year deal with the club.