He made his first-team debut in Finland's top division Veikkausliiga for Helsingin Jalkapalloklubi in 1997.

After Allianssi was drifted to match fixing scandal, Lehtinen returned to Tampere United during the season.

After the season, he traveled to England doing trials for many clubs like Leeds United and also tried to sign contract with FC Honka from Espoo.

However no contract was made and Lehtinen decided to end his football career and concentrate on his job as an investment manager.

He played two games in Atlantis FC in Ykkönen (the second tier) before the contract with Veikkausliiga team AC Oulu was announced.