A deep-lying midfielder, Alonso is a wonderful passer of the ball and has vision to rival any in world football.
A proud Basque, Alonso rose to prominence with hometown club Real Sociedad and has football in his blood. His father, Periko, represented Barcelona and his brother, Mikel, has a spell with Bolton Wanderers on his CV. But after featuring for his country in Euro 2004, Alonso left San Sebastian to become one of Rafa Benitez's first acquisitions as Liverpool manager along with fellow Spaniards Josemi, Luis Garcia and Antonio Nunez. There is no question which player has left the biggest legacy at Anfield.
Winning the Champions League and FA Cup with the Reds, Alonso became a firm fans' favourite following a succession of influential performances but, when Benitez attempted to sell him in order to try and sign Gareth Barry in 2008 (which he failed to do), his relationship with the manager was never the same. After 210 appearances and 19 goals, and despite the 2008-09 season being perhaps his finest for the club, he joined Real Madrid for a fee of Â£30 million to an audible groan of disappointment in the red half of Liverpool.
Strengths: Whether spraying a 60-yard pass to a forward or maintaining possession and dictating the flow of the game, Alonso is an expert manipulator of a football as well as reading the game superbly.
Weaknesses: He lacks any real pace and, the odd spectacular strike aside, does not contribute with enough goals.
Career high: Scoring Liverpool's third goal in the 2005 Champions League final as they famously came from 3-0 down to defeat Milan on penalties in Istanbul.
Career low: Seeing Benitez become determined to sell him in the summer of 2008 in order to bring in Gareth Barry, resulting in his departure from Liverpool a year later.
Style: Controlled, visionary, creative, a consummate passer of the ball.
Quotes: "As a fan, I would say that Xabi is a great player. I think he is the best passer of the ball in Europe." Real Madrid president Florentino Perez, June 2009.
Trivia: Alonso is the only player in modern times to score consecutive goals from behind the half-way line for his club. He first achieved the feat in an FA Cup tie against Luton in January 2006 and his next goal for Liverpool was a soaring 70-yard effort to beat Newcastle's Steve Harper in September of the same year.