Ireland boss Joe Schmidt has hinted that veteran centre Gordon D'Arcy's World Cup berth could be under threat.
Ireland tiptoed past Scotland 28-22 in an engaging but at times low-quality World Cup warm-up Test match in Dublin on Saturday.
Ian Madigan manned Ireland's tiller solidly enough at fly-half as the hosts ran in four tries, moving another step closer to securing his own World Cup spot.
Leinster stalwart D'Arcy struggled to impose any authority at inside centre however, with Schmidt afterwards insisting he does not need two out-and-out 12s in his final World Cup 31.
"To be honest we haven't put any rigidity around those decisions," said head coach Schmidt.
"I think we're reasonably open-minded apart from we do think we'll have a 17-14 split between forwards and backs.
"And how we split that up will be defined by who fits where, and certainly in the backs we're reasonably open-minded about who fits where."
Remaining "open-minded" about his backline carve-up could wind up as bad news for 35-year-old D'Arcy, who made his first Test appearance since last November on Saturday.
Madigan's versatility to cover fly-half and centre, not to mention full-back, could open Schmidt's selection options elsewhere - and D'Arcy could take the full impact.
Robbie Henshaw will start at 12 for Ireland with Johnny Sexton at fly-half, fitness permitting, so Madigan's ability to deputise for both adds an extra card to Schmidt's selection deck.
Ireland's Kiwi boss admitted in midweek that versatility will go a long way to forcing the selection issue, and so it increasingly seems that will prove.
Should D'Arcy's bid for a fifth World Cup campaign fall by the wayside, the 82-cap centre will return to Leinster to boost provincial resources during the tournament, and then retire before Christmas.
Ireland now face a fallow week after two World Cup warm-up victories, where Schmidt admits he will sit down with his fellow coaches for lengthy selection meetings.
Ireland will still face Wales in Dublin and England at Twickenham before launching their World Cup challenge in Pool D against Canada in Cardiff on Saturday, September 19.
Schmidt must submit his final 31-man World Cup squad on August 31, with the Wales clash offering his stars a last chance to impress in Test action before that cut-off point.
The Ireland boss was pleased with Madigan's offering at fly-half, especially in teeing up tries for Zebo and Fitzgerald.
"I think he demonstrated that he can play the position," said Schmidt of Madigan as a fly-half.
"His line-kicking was spot-on; his kicking off the tee was super.
"His pass delivery was very positive.
"There were two crucial involvements in the lead-up to the third try and the crucial involvement in the lead up to the fourth try.
"He'll be reasonably tough on himself and look for more, and he'll have some ideas about what he can do better."