The NFL officially notified the players union on Tuesday that it will opt out of the current collective bargaining agreement, according to ESPN.com's John Clayton. The decision could lead to a season played without a salary cap in 2010 and a possible lockout in 2011. The owners unanimously voted to opt out of the deal, which was extended back in March of 2006. "A collective bargaining agreement has to work for both sides," the NFL said Tuesday morning. "If the agreement provides inadequate incentives to invest in the future, it will not work for management or labor. And, in the context of a professional sports league, if the agreement does not afford all clubs an opportunity to be competitive, the league can lose its appeal."