The NFL said on its Web site a presentation was made during a collective bargaining session Wednesday.
Mark Murphy, president of the Green Bay Packers and a member of the NFL's negotiating team, said if the players agreed to the proposal, it would not be put into place until at least 2012.
Murphy said the proposal included reduction of the exhibition season from four to two games and a bye week would be placed between the last exhibition game and the first regular-season contest.
He also said the regular season would not be expanded unless the players gave their approval.
Although league owners have not taken a vote on the matter, Commissioner Roger Goodell has been an advocate of such a move.
The NFL season was last expanded in 1978 from 14 to 16 games.