Nikos was born in Oak Park, Illinois and started his major junior hockey career with the Belleville Bulls. In 1997 this big defenseman was drafted in the first round by the Carolina Hurricanes, 22nd overall. He moved within the OHL to the Plymouth Whalers and finished his junior career in 1999. He began his pro-hockey career with the Cincinnati Cyclones of the IHL and got his first shot in the National Hockey League in 2001-02 with the Hurricanes. He played in 2 games and registered 0 points and 6 penalty minutes. Tselios spent the next two years with the Lowell Lock Monsters of the AHL and has followed that up playing the last two hockey seasons with the Springfield Falcons, and affiliate of the Tampa Bay Lightning.