Socceroos manager Holger Osieck has identified his best partnership in the heart of defence for Australia's crucial World Cup qualifier against Oman in Sydney.
But the German is not ready to reveal the duo just yet.
Who should partner Socceroos captain Lucas Neill in the back-four has been a question raised more than once as Australia attempts to make it three consecutive appearances at the World Cup finals.
But with Neill missing the Oman game due to suspension, the question has become doubly important.
However, Osieck believes there are better selection quandaries further up the field.
"In my mind, yes I have settled on the pairing," the German coach said. "Knowing that Lucas wouldn't be available for tomorrow I've already worked on this and I'm pretty sure I'm going to have a good pairing in central defence.
"I'm now in a position that I have to admit I really haven't been in before in that I will really have some headaches but positive ones.
"There is a great deal on offer now in terms of players. There's decent quality and players that have made tremendous progress in the last couple of months.
"In recent games at times I have had the problem to really find a good number of players ready for selection but this time the quantity is there and within that quantity I have a lot more quality."
But despite the defensive riddle being answered, there is still the question of qualification for Brazil 2014, and Oman offer the latest in tough tests to face the Socceroos.
"We don't need to talk around the subject - it's a game that we have to win and we go into it in order to win." said Osieck.
Meanwhile, Oman captain Ali Al Habsi believes all the pressure is on the Socceroos heading into Tuesday's clash, with he and his team-mates doing all they can to force an upset.
"The group is wide open. Oman, Australia and Iraq share same points except that they (Socceroos) are ahead of us due to goal-difference. So the pressure is on them and they need to win to see how this tournament really stands," Al Habsi said.
Meanwhile, Oman's top striker Fawzi Bashir has quit the national team on the eve of the crucial clash after a bust-up with Le Guen over his starting XI status.
"It was his decision and I have to respect it," Le Guen explained. "When a massive player becomes a substitute, because I decided it, it's quite difficult to maintain that situation long-term. He's proud and it's difficult for him to accept. I fully understand that."