Born in Hellerup, Piechnik started his senior career with Kjøbenhavns Boldklub (KB) in the top-flight Danish 1st Division.

He joined a struggling Liverpool side, and had a hard time adapting to the English game.

When Graeme Souness was replaced by new manager Roy Evans in January 1994, Piechnik sensed that he was no longer part of the club's plans, and requested a transfer.

He won the 1995–96 Danish Cup with AGF,[6] and was called up to represent Denmark at the UEFA Euro 1996.

[3] He has worked as both a real estate agent and masseur, while still playing "Old Boys" football in Denmark.