Hopes of salvaging the NHL season have taken another blow after owners claimed the players' association had not honoured a promise to continue talking.
The latest round of talks over the long-running pay dispute took place last week, but the NHL says it has not heard from the association since.
"I'm somewhat surprised that I haven't heard from the players' association," said NHL chief legal officer Bill Daly.
"We broke up on Thursday and agreed to keep the lines of communication open."
Daly added: "I'm expecting that at some point we'll hear back from them with respect to some of the concepts that we discussed on Thursday night.
"It's not about the calendar in terms of doing a deal. We're going to have to keep negotiating regardless of whether we can play hockey this season.
"Having said that, each hour that goes by makes it more unlikely that there's going to be hockey this season."
The breakdown in discussions leaves the NHL on the brink of becoming the first North American professional sports league to miss an entire season.
The lockout has already forced the cancellation of 747 of the 1,230 regular-season games plus the All-Star game.
Ted Saskin, the players' association senior director, rejected Daly's claims though.
"Bill knows that the concepts they discussed with us on Thursday would not form the basis for an agreement, so he should not be surprised that he hasn't heard from us," he said.
"We were very clear on Thursday that we would not be negotiating over his proposed concepts."
The NHL is committed to achieving "cost certainty" that would provide a link between league revenues and player costs but the players' association refuses to accept such a move.
The dispute has now been running for 138 days.