Cardiff City FC will get a further four-month extension to produce more information for the local council about its proposed 30,000-seat stadium.
The new stadium is planned for land next to Ninian Park
The club now has until the end of September to produce outstanding financial information following an earlier deadline of 31 May.
The council said it needed more details after financial consultants examined a business plan for the proposals.
But it said the scheme "continues to move in the right direction".
The club, which last season faced a financial crisis, plans to build a 30,000-seat stadium - which could rise to 60,000 - on land at Leckwith, next to the club's current Ninian Park ground.
Integral to the scheme is securing a shopping development. American discount store group CostCo has signed a contract to become a tenant, but other stores are needed to join the project.
In January, Asda was unveiled as the cornerstone outlet for the shopping scheme behind the proposed stadium.
In March, the council gave the club an extension until the end of May to submit a detailed business plan after doubts were expressed about the viability of the proposal.
That extension has been increased until the end of September to allow the council's consultants Deloittes time to consider additional financial information. This includes a revised business plan and information on costs, receipts and funding related to the overall financial viability.
The 30,000-seat stadium could in future reach 60,000 capacity
The information has been assessed but more time is needed to finalise details.
Cardiff Council chief executive Byron Davies said he would recommend the club is given until 30 September to provide the outstanding financial information.
"This project is still continuing to move in the right direction but the council must make sure that it is completely satisfied about the viability of the stadium project," he said.
"On this basis the deadline has been extended to allow us to work with the club and get the additional financial information we need.
"Both Cardiff Council and CCFC remain fully committed to delivering a stadium and this extension shows how positively this complex project is moving forward," he added.
The decision whether to extend the deadline will be made at a special meeting of the council's executive on 22 May.
Council leader Rodney Berman said: "Things are continuing moving forward and it's important now, if the extension is agreed, that the club provides us with any additional financial information still required to move this onto the next stage.
"I can't stress enough how much progress has been made in the last few months and hopefully this extension will resolve the remaining issues and details that need to be ironed out."
The club last season faced £30m debts and sold several players to reduce the wage bill.