Bolton and Bury's opening League One games are "likely" to be suspended if they do not meet a new English Football League deadline to provide evidence of their financial viability.
Both clubs have until 17:00 BST on Monday to show they can meet "all outstanding commitments".
Bolton have been in administration since 13 May, with a protracted takeover still not complete.
Bury's initial deadline of 12:00 BST on Monday has been extended by the EFL.
Wycombe - who are due to host Bolton on Saturday - have already suspended ticket sales to away fans. Bury are scheduled to play MK Dons at Gigg Lane.
Both will start the 2019-20 campaign with 12-point deductions resulting from their financial difficulties.
While the EFL says "some progress has been achieved" with the clubs over the weekend, concerns remain over "the respective challenges they currently face".
"The EFL will continue to offer its full assistance and support to both clubs in order to achieve the objective of securing long-term futures for them," a statement said.
"But with the season now a matter of days away there is no other option but for all outstanding matters to be brought to a conclusion."
On Wednesday EFL executive chair Debbie Jevans said Bolton's situation was a "significant concern", with the club having three pre-season friendlies cancelled.
A group of Bolton players expressed discontent over the takeover of the club earlier this month, saying they had gone without pay for "20 weeks", leading to matches against Chester and Preston being called off.
Bury, meanwhile, need to give details of how they plan to settle their debts after a company voluntary arrangement (CVA) was approved by creditors on 18 July.
The Shakers are still looking for new ownership after Steve Dale put the club up for sale in April.
They are also due to reappear in the High Court on Wednesday after a winding-up petition taken on by HM Revenue & Customs over an unpaid tax bill was adjourned in June for a third time.