Worcester, burdened by debts of over £25 million ($28 million, 28 million euros), have until Monday to avoid suspension from all competitions by convincing England's governing Rugby Football Union by providing evidence of required insurance cover, the funds to meet payroll and a plan to end their financial crisis.
Warriors rugby director Diamond said recent days at the Midlands side had amounted to a "period of near-purgatory", amid a rising tide of anger towards co-owners Colin Goldring and Jason Whittingham,.
Diamond, speaking at a pre-match news conference on Friday, said: "Our mindset tomorrow is that it's our last game at Sixways, ever.
"I am really proud of the lads going out tomorrow. There is no team-talk needed.
"And we are going out into Worcester tomorrow night for a pint as a team. We are going to find some nice little bars and nightclubs for older gentlemen like me to stand in the corner."
Culture minister Stuart Andrew told lawmakers on Thursday the British government would put the Warriors into administration if it was the "most viable option" to save the club.
Diamond added Friday that the current situation was unsustainable, with many Worcester players and staff yet to receive their full salaries for August.
"We have been in this period of near-purgatory for a while now, and it is starting to come to a head, no doubt with us potentially being suspended on Monday," he said. "It is sad, and it is diabolical that it has been allowed to walk itself to the graveyard, virtually."
Diamond said he sympathised with the position officials would face if Worcester were suspended as "you can't have a team not playing five or six games and put them back in".
But the former Sale supremo said were suspension and entering administration to happen, Worcester could be back up and running within weeks.
"If the right investor with the right capital investment, working capital money, comes in, then you wouldn't have to be Warren Buffett (the American billionaire businessman) to turn it round," he said.
Worcester are not the only one of the Premiership's 13 clubs facing financial collapse.
Wasps, twice European champions, announced Wednesday an intention to appoint administrators after failing to meet a May deadline to repay £35 million in bonds, which helped finance their relocation to Coventry from London in 2014.
