Liberopoulos is a unique player in Greek domestic football, as he is equally adored by fans of both AEK Athens and Panathinaikos.

After an impressive debut season in Greece's top division, AEK Athens and Olympiacos tried to sign him during the summer of 1996 yet Panathinaikos managed to snap him up.

Italian clubs, mainly Juventus and Hellas Verona showed interest in hiring him, but his loyalty to Panathinaikos kept him in Athens.

Following his departure from Panathinaikos he was ready to join Sochaux, but he finally chose AEK Athens where he became a formidable offensive player and inspirational leader.

Club president, Demis Nikolaidis had publicly announced his intent to retain Liberopoulos at all costs in an effort to bolster AEK Athens' chances at achieving dominance in the Greek Super League.

[4] On 30 May 2011, Liberopulos won his first trophy in his career with AEK winning the Greek Cup 2010–11 against Atromitos 3–0 while also scoring the first goal and was awarded MVP of the match.

[5] Also, his teammate Traianos Dellas decided to stay for one year at AEK, in order to stop his professional career with his best friend, Liberopoulos.

Liberopoulos has been known on the international scene as a "super sub", coming off the bench many times in the final quarter of games and scoring the decisive goal.

On 11 September 2009, Liberopoulos announced his retirement from international football,[8] But he returned to the national squad about a year later when he was recalled by the new coach Fernando Santos.

Liberopoulos announced his retirement from international football after Greece lost to German 4–2 in the Euro 2012 quarter finals on 22 June 2012.