“The Management Council Executive Committee determined that the contract practices of a small number of clubs during the 2010 league year created an unacceptable risk to future competitive balance, particularly in light of the relatively modest salary cap growth projected for the new agreement’s early years,” the league said in a statement Monday. “To remedy these effects and preserve competitive balance throughout the league, the parties to the C.B.A. agreed to adjustments to team salary for the 2012 and 2013 seasons. These agreed-upon adjustments were structured in a manner that will not affect the salary cap or player spending on a leaguewide basis.”

On Monday evening the Redskins and the Cowboys released statements, with the Redskins sounding as if they were prepared to dispute the findings:

“The Washington Redskins have received no written documentation from the N.F.L. concerning adjustments to the team salary cap in 2012 as reported in various media outlets,” the Redskins executive Bruce Allen said in a statement. “Every contract entered into by the club during the applicable periods complied with the 2010 and 2011 collective bargaining agreements and, in fact, were approved by the N.F.L. commissioner’s office. We look forward to free agency, the draft and the coming football season.”

The Cowboys’ statement said: “The Dallas Cowboys were in compliance with all league salary cap rules during the uncapped year. We look forward to the start of the free agency period where our commitment to improving our team remains unchanged.”

But the salary cap might have been much lower. The union and the league were negotiating the salary cap, as they do every year. About a week ago, the union representatives learned for the first time that the league wanted to punish the Redskins and the Cowboys for their behavior during the uncapped year. At one point, there was discussion of taking draft picks from the teams. The league also considered taking money off the cap from the teams, but not dividing it among other teams — essentially taking it out of the system that pays players. The union objected, and during several days of haggling, which delayed the announcement of the salary cap until just days before free agency began, there was the possibility that the salary cap could have dropped to as low as $115 million, not including benefits — which would have been a substantial blow to the union. In the end, the union and the league agreed to set the salary cap at $120.6 million in exchange for the league punishing the Cowboys and Redskins, while redistributing the cap space to the rest of the teams in the league.

An example of the salary dump: in 2010, the Cowboys paid receiver Miles Austin $17 million in salary, which means all of it counted in 2010 and none was prorated over subsequent years, when the salary cap returned after the new labor agreement was reached last summer.