The Wellington Phoenix fear a travel delay to Australia may severely compromise their efforts to complete their best ever A-League season.

Football Federation Australia announced on Monday it had agreed with the 11 clubs and the PFA an extension of the season until August 31 with matches to begin in mid-July, followed by a finals series.

The proposal requires Wellington's players and staff to relocate to New South Wales until the end of August, the first two weeks of which will be spent living and training in quarantine. But the club received a bombshell on Monday when they learned clearance had not been granted for them to enter Australia.

Football Federation Australia had been negotiating with NSW health officials to grant an exemption for the Phoenix to enter, similar to that given to the Warriors to continue their NRL season.

"We had been receiving a number of assurances this was all underway and would be expedited through, a la the Warriors, but this afternoon we've found out it still has not been approved," said Phoenix General Manager David Dome.

"We were under the impression the NSW government understood the urgency behind (our entry) and we were fully expecting it to be (sorted) over the weekend or at the latest, Monday.

"We found out Monday afternoon things haven't progressed and we're looking at late Tuesday before we get any idea of whether we'll be able to get into Australia.

"We're not Sydney FC, we're not coming from just down the road. We have to spend time booking our flights to get there, then do our Covid testing and wait 48 hours for the results of that to come back before we can start training.

"Some clubs have picked up training today, so if you work backwards from those timelines, you're looking at 6-7 days before we can start training. That's one week of a four-week window we've lost due to bureaucracy and road-blocks being put in our way.

"It's extremely disappointing given we will be making a greater sacrifice than any other club," said Dome.

Adding to the frustration is that club bosses are completely in the dark as to the reason for the hold-up.

"We can't get an answer," Dome said.

"We're not being given a reason why this hasn't been processed through. We're coming from a Covid-free country to Australia where we're going to have to put some fairly serious protocols in place to ensure the safety of our players and staff and yet we still can't get in.

"The implications of us not being able to get there in time to do our training are pretty serious for us. We're just disappointed that message isn't getting through."

An FFA spokesperson told the NZ Herald through a statement the process is ongoing.

"We are working through a complex process with Government to grant Wellington Phoenix an exemption and move them to a private training facility. Given we are dealing with public health the matter is neither straightforward nor can it be rushed."

The Phoenix have already spent time in quarantine once this year, travelling to Sydney in mid-March in an attempt to continue the A-League season, before it was called to a Covid-enforced halt.

During that time, defender Tim Payne was charged with drink-driving charge after a late-night joy ride in a golf cart. Payne entered a guilty plea last week and will be sentenced later in the month. Dome says the incident has played no part in negotiations around the Phoenix's return to Australia.

"This is part of the challenges Wellington as a club has always faced," Dome said.

"They've put out a press release (announcing) the season is ready to go, but they haven't considered the implications of not having the Wellington Phoenix being approved to enter Australia.

"We've done the work from our side, we've got work visas in place for all players that need them and we've built our protocols for once we arrive. The disappointing thing is we can't get any traction from the NSW government to let us in so we can actually begin the process of the quarantine."

FFA's release announcing the restart noted negotiations with broadcaster Fox Sports were still ongoing, which has been the major sticking point in the resumption of the season. Dome expected further clarity on those discussions on a conference call with other club CEO's on Monday evening.