Complex sentence: The 2004-05 regular season has not yet begun but its start may be delayed due to the current status of the NHL's Collective Bargaining Agreement set to expire in September and the NHL and NHL Players Association not yet agreed to a new contract.
Split into simpler sentences: The 2004-05 regular season has not yet begun but its start may be delayed due to the current status of the NHL's Collective Bargaining Agreement which is set to expire in September. The NHL and NHL Players Association have not yet agreed to a new contract.