In the last seven days, both Renault and Red Bull have admitted - not for the first time - that they, and sister team Toro Rosso, could walk away from F1. Then again, in terms of the French manufacturer it has already done so... on numerous occasions.

Last year we almost lost one team, but thankfully a consortium led by Canadian billionaire Lawrence Stroll stepped, and other than the mounting problems facing Williams, there is concern at Haas' increasingly political approach, that and the fact that one point team owner Gene Haas is going to realise that fifth, possibly fourth, in the standings, is as good as its ever going to get.

Then there's Mercedes, after just two practice sessions it is clear the German tem could be heading towards its sixth successive titles, should it achieve this, and then go on to score a seventh in 2020 - thereby setting a new record for the sport - will it opt to walk away and throw its full resources into its Formula E programme?

At a time one can argue that the future of four or five teams is in doubt, Chase Carey insists that he has "real interest" from new teams looking to enter the sport.

"It is one of our strategic goals," he said at a joint press conference with Jean Todt in Melbourne, "we want to make the sport more attractive to potential new entrants.

That is a key goal we have," he added. "It is certainly a goal in the 2021 regulations. I think we've got to solidify those regulations to have those discussions.

"I've had a number of, more on the team side than the engine side, a number of potential new entrants that have expressed interest and enthusiasm if we provide a structure that they think enables it to be something they could enter more constructively," he said. "I do think there's actually interest on the team side, but I think we have to finalise what it looks like so they can evaluate it accordingly.

"I think priority one before we get two new teams coming in is to make sure it's quality over quantity, and make sure we make the business as strong as we possibly can for the teams that we have in it. I think we can go a long way in doing that. I think there is interest.

"I think there really is interest if we can provide a framework that they feel from a business and a competitive perspective is attractive to them. But I think there is real interest."

Whatever he might think, while much depends on the sport successfully introducing its plans for the redistribution of the prize pot, the scrapping of historic bonuses and the introduction of a budget cap, the fact is that while some teams already appear to be looking for a possible way out, prospective new entrants only have to look back at the (false) deal sold to the last batch of new entrants in 2010, all three of them lured by the promise of cheap engines and a budget cap, all three of them long dead and buried.

Check out our Friday gallery from Melbourne, here.