Papadopoulos started football in 1974 from the amateur team Eleftheriakos Eleftherion, while he became more widely known competing in the AEL from 1979.
In 1988, even though he was a key player in the team for years, his career at AEK suddenly came to an end.
On the eve of the cup rematch against Olympiacos, former AEK footballer Dinos Ballis visited the AEK team's hotel, offered a bouquet to Papadopoulos and was eventually suspected of attempted bribery.
The owners of Olympiacos, the Koskotas brothers and Dinos Balis, as an intermediary, were accused of attempting to bribe the AEK players, Papadopoulos and Vasilakos.
He played for the club of Nea Smyrni until 1992 and eventually ended his career in 1993 at Ionikos.