Ireland's Six Nations opener is now less than five weeks away with the debate over the centre pairing set to continue until Joe Schmidt names his team to face Wales on February 7.
Both of Ulster's current midfield combination, Stuart McCloskey and Luke Marshall, were in Carton House at Ireland's training camp this week with McCloskey tipped for a first senior cap in 2016.
For years the names of Brian O'Driscoll and Gordon D'Arcy were inked onto the team-sheet but in their absence it was Jared Payne and Robbie Henshaw who contributed to last season's championship victory and were the presumptive midfield duo for the World Cup before injury intervened.
With Payne sidelined since breaking his foot at that tournament, his position in the outside centre berth is under threat, even if he manages to return to action for Ulster this month.
With Henshaw capable of playing inside or outside centre, as well as full-back, there is potential for him to be shifted further along the backline and, if he were to be handed the 13 jersey, it could open the door for McCloskey.
No less a figure than Lions legend Sir Ian McGeechan has endorsed the candidacy of the hard-running Bangor man.
"With Jared Payne still injured, there will be an interesting debate as to who should play alongside Robbie Henshaw at centre," said McGeechan.
"But the one player I would look at closely is Ulster's Stuart McCloskey. He looks to me like a big, powerful man with good hands, and Ulster look the best of the provinces, so I would be looking at them first.
"Ireland are in transition, and I think that Joe Schmidt really needs to have a rethink.
"The calamitous World Cup quarter-final defeat by Argentina was, notwithstanding the injuries they suffered, one of those moments after which a coach sits down and realises that things must change.
"Ireland's narrow game was found out and I think they must now redefine themselves.
"The loss of Paul O'Connell will be sorely felt, and with prop Mike Ross struggling to be fit in time, it looks as if Ireland's front five might not be as formidable as they have been.
"It does not help Schmidt's job that at the moment the Irish provinces are not exactly tearing up trees. A lot of responsibility will fall on the likes of Rob Kearney, Jonathan Sexton, Conor Murray and Jamie Heaslip."
McCloskey was not the only young centre exposed to the Irish set-up for the first time on Sunday with Leinster's Garry Ringrose also in attendance.
Having impressed in sporadic cameos for Leo Cullen this season - the Blackrock College product's minutes were limited of late due to the academic commitments of a full-time student - he played a starring role for his province in the inter-pro victory over Munster.
His contribution drew praise from O'Driscoll, who tweeted: "Irish Rugby could do a whole lot worse than going with Garry Ringrose against Wales."
When Henshaw and Payne missed games at the World Cup, Darren Cave, Luke Fitzgerald and Keith Earls all saw time in the midfield and remain options.