The NHL and the players' association had no communication Monday and have not been in contact since talks broke off before the weekend, sources within the league and union confirmed to the Canadian Press.
Another source told the CP that the players' association will not initiate contact so the NHL will instigate more talks this week before it's too late to save the season.
The sides parted ways Friday after three straight days of negotiations.
So far, the NHL board of governors hasn't set up a meeting, but that is not a necessary step for the season to be called off, a source told The Associated Press.
Through Monday, the 4½-month lockout has wiped out 799 of the 1,230 regular-season games and the All-Star Game.
The sides have a major stumbling block -- a salary cap. The NHL has insisted on a link between league revenues and player costs, and the players' association has steadfastly refused that as a solution.
Commissioner Gary Bettman and players' association executive director Bob Goodenow rejoined the negotiations Thursday after sitting out the previous five bargaining sessions. The sides met for 13 hours during the last two days of talks.
On Wednesday, the players' association quickly rejected the league's latest proposal because it included a salary cap. But right after that meeting, the union invited the league back to the table and wanted the leaders there.
No major league in North America has lost an entire season to a labor dispute. The Stanley Cup has been awarded every year since 1919, when a flu epidemic wiped out the final series between Montreal and Seattle.
Information from The Associated Press was used in this report.