A legal missive sent to Cricket Australia is as "serious as it gets" and suggests Seven is genuinely ready to end its $450 million commitment to broadcast the sport, according to industry expert Colin Smith.
It has been a fortnight since Seven West Media chief executive James Warburton threatened to pull out of his network's six-year deal to broadcast BBL and Tests, describing CA as "the most incompetent administration" he has ever worked with.
At that stage it was all talk, but the feuding parties both sought legal advice as Seven ramped up its push for a discount to its annual fee.
Seven has now formally outlined its objections about this summer's proposed schedule in a letter to CA, arguing the governing body is in breach of its contract.
Smith, one of Australia's eminent sports media-rights strategists, believes it would be wrong to dismiss the letter as a negotiating tactic.
"You don't come out with those things unless you're willing to walk. Nobody can adopt the ostrich-style of management in response to this," the managing director of Global Media and Sports told AAP.
"That's as serious as it gets.
"The balance sheet of Channel Seven would force their hand to a certain extent. It's not like they can say 'it doesn't matter; whatever we pay, we'll pay'.
"I'd read into it there is a desire to walk away and if they do retain it then they'll be looking for a very, very significant discount."
CA has repeatedly vowed it will deliver a full season as promised while refusing to offer any form of reduction in fees - let alone the big discounts that AFL and NRL gave broadcasters because their seasons were affected by COVID-19.
Seven's next payment to CA, worth approximately $25 million, is due on Tuesday but it looks increasingly likely that it won't be paid.
If mediation and arbitration fails then the prospect of a costly court battle is on the cards.
The brinkmanship comes approximately a fortnight before the international summer is due to start with a women's trans-Tasman clash in Brisbane, which is meant to be broadcast by Seven.
"Cricket Australia remains in ongoing discussions with the Seven Network about delivering a compelling summer of cricket," a CA spokesperson said.
"CA is committed to fulfilling its contractual obligations to all its partners."
It has been a winter of discontent for CA, which cut costs, removed Kevin Roberts as chief executive and axed 40 staff.
Smith noted a "minute to midnight" search for a new free-to-air partner would present plenty of challenges for CA - and a major drop in revenue.
"Channel Nine has said it'd be interested at the right price ... but it can't conflict with its tennis coverage," he said.
"I doubt whether Ten would come in. You never say never.
"But the previous chairman of Cricket Australia called them bottom feeders in the last bidding process ... people at that network are unlikely to forget."