Joe Calzaghe insists a super middleweight unification bout with Jeff Lacy is far from a done deal.
IBF champion Lacy impressed in stopping Robin Reid last week with his promoters saying he would face long-reigning WBO king Calzaghe in Wales on 5 November.
But Calzaghe has to get past a bout with an as-yet unnamed opponent in Cardiff on 10 September.
He says the Lacy fight will go ahead, but that the suggested 5 November date has "many obstacles" in its path.
"That date has come from America," said Calzaghe in his column for the South Wales Argus.
"Wales play the All Blacks in a rugby international in Cardiff's Millennium Stadium on that date."
That creates problems over a venue and hotel space, and if the proposed date goes ahead it is likely to be in either Birmingham or London.
The capital's ExCel Arena would be favourite, with Birmingham's National Exhibition Centre and the National Indoor Arena in the running.
But Calzaghe was realistic in his assessment of other potential pitfalls ahead of the match being made.
"Lots of things can also happen between now and then, not least among them injuries," said the champion from Newbridge.
"I have had problems with my hand and back on and off over the years, which is hardly surprising when you have been fighting since the age of nine like I have.
"My left hand swells up after almost every fight - though it was fine after I stopped Mario Veit in Germany last time out - so I don't want to put the cart before the horse and it's vital I keep focused on 10 September.
"Don't get me wrong, the Lacy fight will go ahead. He wants it and I want it and the prospect really excites me, but I haven't even talked money yet so nothing is cut and dried.
"Lacy looked good coming forward against Reid, but let's see how good he is when he's being backed up.
"I certainly saw weaknesses in his armoury and, though I'll have to be at my best to beat him, I still don't believe there's a super middleweight on the planet who can live with me."
Calzaghe says he expects to hear who his 10 September opponent is within the next few days.
It will not be Scott Pemberton, though, who has agreed to fight Danny Green in Perth in October.
Canadian Otis Grant has also been ruled out, with former WBA champion Manny Siaca and Denmark-based Kenyan Evans Ashira the latest names mentioned.