The Candystripes play their last home game of the season on Friday when they host Sligo Rovers.
However, the club still do not know when work on a multi-million pound redevelopment of their stadium will begin.
Derry City and Strabane District Council, who own the stadium, said a tendering process is ongoing.
Club chairman Philip O'Doherty said he is concerned that Friday's game could be the club's last at Brandywell for some time.
"The ideal situation would have been that, after this last home game, the diggers would be in the next day," Mr O'Doherty said.
"That's not going to happen, the longer construction work is delayed the less games we will play at Brandywell next season.
"That means that the possibility of having the European tie at Brandywell is basically under threat at the minute," he added.
Derry City secured their place in next season's Europa League competition with last week's 2-1 victory over Bohemians.
Brandywell 2016 Timeline
Earlier this year, Derry City sought out venues for the relocation of six home games which would be affected by the redevelopment.
Since then, the Brandywell delays have left talks with other clubs 'up in the air', Mr O'Doherty said.
"We have no clarity from Derry City and Strabane council which is extremely frustrating.
"The club has been slaughtered on social media about holding things back but I do not know when this project will start.
"Derry City Football Club is also a business and it is not a good situation for the club to be in."
A spokesperson for Derry City and Strabane District Council said: "The tender process for the appointment of a contractor for the Brandywell Stadium redevelopment and dog track is ongoing.
"Council is hopeful that these processes will be concluded shortly," they added.
Although Friday's tie with Sligo Rovers is the last home game for Derry City, other stakeholders at Brandywell - which include a greyhound track - have use of the stadium until at least the end of November.
That means construction could be delayed further.

The claim: The pound is up and the FTSE 100 share index is at the same level as it was in March.
Reality Check verdict: Nigel Farage is right about the levels compared with March, but looking a few months further back and considering options markets may give a more useful view of concerns on the currency markets about the risks of a Brexit.
Mr Farage said: "Sterling is up since March. Since Brexit became a possibility, sterling is up and FTSE is exactly the same level it was in March.
Let's have a look at the value of the pound against the euro first. It was below the level it is now towards the end of March.
But was March a good month to compare it with? The Bank of England's quarterly inflation report in May blamed half of the fall in the value of the pound since November on uncertainty about the referendum. It's now fallen by about 11% since November.
There have also been signs on the options markets that traders have concerns about a depreciation in the pound. Bank of England governor Mark Carney told a parliamentary committee in March that there had been big increases in traders buying options as protection against falls in the pound in the coming months.
The FTSE 100, meanwhile, is also trading at levels it saw in March, although it is less clear how closely tied the index is to the state of the UK economy - many of its biggest components are multi-national companies, more affected by commodity prices than whether the UK stays in the EU.
There are various forecasts for what would happen to the pound if the UK left the EU.
The National Institute of Economic and Social Research predicted that by 2030 one pound would be worth about one euro, which would be a depreciation of more than 20%, but that comes with the usual caveats about the uncertainties surrounding forecasts and economic modelling.
Read more: The facts behind claims in the EU debate
The chairman of Derry City Football Club has warned that European football at Brandywell stadium is under threat.
[NEXT_CONCEPT]
UKIP leader Nigel Farage was asked on the Andrew Marr show about Friday's falls on the markets and whether it was to do with fears about the UK leaving the European Union.