Kearney is the incumbent and Zebo had his shot against Wales
Last night, former Ireland captain Keith Wood spoke of his belief that Simon Zebo had shown enough against Wales to warrant another run-out at full-back.
With the caveat that the Munster wing's performance had shown both excellent qualities and also far less desirable errors, he told Off The Ball that having a "strike runner" at 15 can add an extra element in attack.
However, normal service has resumed for the France game with Zebo not named in the matchday 23 by Joe Schmidt and Leinster's Rob Kearney back in the position that he has occupied for so long and with distinction.
Zebo and Kearney are clearly very different players in their approach to the game, although the sample size at 15 leans towards the Louthman given his huge experience in the role.
Against Wales on Sunday, Zebo beat four defenders and made ten carries in a match which saw him gain 82 metres.
He also managed one clean break. But as Keith pointed out, he made his fair share of glaring errors.
However, all the good and the bad is just based on one game and a particular set of opposition and tactical demands.
As The Irish Times' Gerry Thornley assessed it, "I really am excited by Simon Zebo at full-back at times. I think his lines of running last weekend, the way he came at the ball at such pace really gave Ireland another weapon that we haven't seen in a while. But of course he's not as good in the air or as physical in the air as he could be like Rob Kearney is."
Kearney played in every match of last year's Six Nations and if you look at the average statistical numbers from those performances at full-back, they tend to match up reasonably well in attack with the man who filled in for him in purely numbers-based terms.
He made an average of 68 metres - with his high of 98 metres coming away to Wales - and had just one clean break throughout the championship, coming in the first match against Italy.
As for carries, while Zebo had 10 against Wales in the smallest sample size, Kearney average over five 2015 Six Nations matches were 11.6.
As for the ability to beat defenders, Kearney averaged a shade over two defenders beaten per game. But as Gerry Thornley emphasised, Kearney's fielding and aerial ability have been a boon.
It is more a question for the future given that the Dundalk native is still just 29 and Zebo is a full four years younger, if it is a case that the latter's long-term international future resides at 15 than on the wing.
No need for a crystal ball this weekend though given Schmidt's selection is known!