Scarlets head coach Simon Easterby is concerned after the latest instalment of cash for playing in the Heineken Cup was delayed.
The four Welsh regions are expecting £200,000 each from European Rugby Cup, the company which runs the tournament.
ERC said payments were not due until after a meeting on 5 February, but that deadline has been moved to 19 February.
"It's a large chunk of money that goes towards cash-flow and making sure the business runs smoothly," Easterby said.
"Two hundred grand is probably a drop in the ocean to some French clubs but to us and other regions it's a lot of money, and it's money that currently we can't afford not to have."
The board of ERC are understood to be withholding money as they seek to clarify what liabilities they would suffer should the company be forced to wind up in the summer.
ERC issued a statement on Wednesday confirming that no money would be released until at least 19 February, when its board will meet again to discuss the issue.
"The directors of ERC voted unanimously at a board meeting in Dublin today (Wednesday, 5 February) to postpone all decisions including the release of further instalments of ERC's distributable central revenues to the six shareholder countries until 19 February next, when the board will meet again to reconsider the issue," read the statement.
"The board agreed unanimously that further detailed legal and other professional advice was necessary in order to facilitate the ongoing discussions in relation to the future of European club rugby tournaments and the distribution of funds deriving from the 2013/14 season."
The board of ERC is made up of club and union representatives from England, France, Ireland, Italy, Wales and Scotland.
The Welsh regions - Ospreys, Scarlets, Cardiff Blues and Newport Gwent Dragons - were represented on the board by Regional Rugby Wales (RRW) chief executive Stuart Gallacher, who has since resigned from it.
The governing unions in Wales, England, Ireland, Italy, Scotland and France have committed to a new Heineken Cup tournament, which would be shown by current broadcast partners Sky.
The English Premiership clubs insist they will not take part and have proposed a rival cross-border competition, the Rugby Champions' Cup which would be broadcast by BT.
The Welsh regions favour the new tournament as they claim it guarantees them extra revenue, putting them at odds with the Welsh Rugby Union.
ERC owe the English clubs £1.6 million with Premiership Rugby saying they will now seek advice on whether ERC's decision constitutes a breach of contract.
"We believe this inflames the issues we have in coming to a European solution and the next step is for Premiership Rugby to take advice to see if this action represents a fundamental breach in the contract between ERC and its clubs," said PRL in a statement.