The quarrelsome relationship between the NFL Players Association and the NFL continues to go downward. Last week, New Orleans Saints LB Jonathan Vilma sued NFL Commissioner Roger Goodell for defamation. Today, the NFLPA filed a federal lawsuit alleging that the league and its owners conspired in collusion to establish a secret salary cap in 2010.

NFL spokesman Greg Aiello (pictured left) responded to the lawsuit, saying, "The filing of these claims is prohibited by the Collective Bargaining Agreement and separately by an agreement signed by the players' attorneys last August. The claims have absolutely no merit and we fully expect them to be dismissed.

"On multiple occasions, the players and their representatives specifically dismissed all claims, known or unknown, whether pending or not, regarding alleged violations of the 2006 CBA and the related settlement agreement. We continue to look forward to focusing on the future of the game rather than grievances of a prior era that have already been resolved."

NFLPA executive director DeMaurice Smith has a different view, releasing the following statement:

"When the rules are broken in a way that hurts the game, we have an obligation to act. We cannot stand by when we now know that the owners conspired to collude."

The union is seeking an estimated $1 billion in damages.