The FA would be required to sign off the licence transfer if the EPL side swoop for the ladder-topping A-League minnows.

And FA chief executive James Johnson is thrilled by the prospect of potentially having a Manchester City-linked club in Melbourne and a Manchester United-linked club in NSW.

"It's exciting, isn't it?" he admitted today at the launch of a new Matildas and Socceroos sponsorship deal with Commonwealth Bank.

"It's a very competitive relationship all over the world so that would be interesting!"

United's interest has been downplayed by the Mariners as "speculation" and "noise" while discussions are said to continue.

Football Australia refused to comment on their involvement in any possible deal, but it is understood they have already been in talks over the possibilities it throws up.

The unbundling of the A-League from Football Australia has meant expansion and licence transfers is a two-pronged deal with approval needed from rival clubs via the Australian Professional Leagues body which runs the A-League now, followed by sign-off from FA.

A key stumbling block though could be a proposed relocation from the Central Coast to the the north shore of Sydney.

Possible stadiums for the new entity would be problematic though with North Sydney Oval used for cricket during the summer and Brookvale stadium too local to the Northern Beaches with limited access and transport links to the rest of northern Sydney, especially the north-west of the city.

There is also a potential backlash over the Central Coast being abandoned for a fourth Sydney side, while Canberra and Tasmania continue to wait in the wings.

But the FA is not willing to rule anything in or out yet.

"It's too early to talk about that," said Johnson today. "What we need to talk to the clubs about and what the clubs need to really consider is what the strategy is.

"And then for me, there's always a commercial angle yes, but there's also a football angle. What's best for football? That's gonna be part of the conversation.

"And then we've also got to look at the geography as well. Those discussions need to happen before we jump into where the team is going to be.

"We've got to sit down with the clubs and really thrash that out."