Early years Liberopoulos started his career football career at the local
Erani Filiatra, he then moved to
Kalamata in 1994. 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.
Panathinaikos In summer 1996, Liberopoulos signed for Panathinaikos. With them he reached the semi-final stage of the
UEFA Champions League. Italian clubs, mainly
Juventus and
Hellas Verona showed interest in hiring him, but his loyalty to Panathinaikos kept him in
Athens. In 2003, Liberopoulos clashed with Panathinaikos' board which eventually led to him leaving the club. While at Panathinaikos he would deliberately misplace passes to his colleague Marco Villa because he saw him as more of a threat than a teammate.
AEK Athens Following his departure from Panathinaikos he was ready to join
Sochaux, but on 31 July 2003 Liberopoulos signed for AEK Athens. He went to score several times against his former team but never celebrated earning the fans' applause and a standing ovation for his action. He helped AEK Athens scoring 79 times in his 195 appearances and earning a top scorer award during the
2006–07 season. His most important goals originated from two long range shots, one in a 1–0 win against
Lille and another in a 4–0 with against
Olympiacos. During June 2007, Liberopoulos was offered a lucrative contract with
1. FC Nürnberg worth 4 million euros, which he declined to remain with AEK Athens. 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. On 7 July 2008, Liberopoulos was released by AEK. German team
Eintracht Frankfurt announced his signing on 13 July 2008.
Eintracht Frankfurt On 13 July, Liberopoulos signed a two-year deal for
Eintracht Frankfurt and was given the number 10 shirt. He made his
Bundesliga debut, playing the full 90 minutes against
Hertha BSC on 17 August 2008 at the Commerzbank-Arena in Frankfurt. Liberopoulos scored his first goal against
Mainz 05. He won 55 caps scoring 13 goals in all competitions.
Return to AEK Athens In the summer of 2010 Liberopoulos returned to
Greece and AEK Athens. He put in an impressive display in AEK's 5–3 win against Australian
A-League club
Sydney FC on 25 July 2010, scoring one goal and setting up two others. Liberopoulos also scored against
Blackburn three days later. He made his league debut against
Kerkyra and scored his first official goal in a
UEFA Europa League match against
Hajduk Split. On 19 January 2010, in a
Greek Cup match against Panathinaikos he scored two goals leading his team to victory. Liberopoulos was applauded during his substitution later in that game by some of Panathinaikos' fans despite their team's defeat. After the match Liberopoulos said "I have spent seven nice years in Panathinaikos in which I matured as a player. I keep only the positive things, but now for me AEK is my family and I will do everything for the team." and about the Panathinaikos' fans ovation "It means a lot to me. It's a great feeling to be applauded during your substitution. There were some hoots also but even if the whole stadium was hooting at me that would not have changed what I have said earlier about my feelings for Panathinaikos". On 30 May 2011, Liberopulos won his first trophy in his career with AEK, winning the
Greek Cup in 2011 against
Atromitos 3–0 while also scoring the first goal and was awarded
MVP of the match. On 16 June 2011, Liberopoulos signed a new one-year deal keeping him at the club until 2012. His teammate
Traianos Dellas decided to stay for one year at AEK as well, in order to stop his professional career with Liberopoulos. On 20 May 2012, he played his last match with AEK against Panathinaikos. A lot of Panathinaikos and AEK fans respected him with a standing ovation when he was exiting the stadium. ==International career==