Joe Schmidt could kick the November series off with a major surprise by pairing Robbie Henshaw and Jared Payne in the Ireland midfield when he names his team to face the Springboks tomorrow.
The duo had been thought to be competing for the No 13 jersey vacated by Brian O'Driscoll at the end of last season, and debate has raged over which of them would get the nod against South Africa.
However, Schmidt looks set to throw a major curve-ball by selecting them both for the opening game of the autumn internationals, with their combined physical presence a big attraction.
That would mean disappointment for Gordon D'Arcy, who suffered a groin injury during Leinster's Champions Cup game against Castres and missed a number of last week's Ireland training sessions since the team came into camp.
That, combined with the concussion that limited Stuart Olding's involvement, appears to have allowed Connacht's rising star Henshaw and Ulster's naturalised Kiwi Payne to partner up, and it appears Schmidt liked what he saw.
Rory Best remains the coach's main injury concern after he sat out training yesterday. Sean Cronin is the favourite to come in at hooker if the Ulster man fails to recover from his calf problem in time.
Rob Kearney came through training along with Johnny Sexton and both are expected to play, but the full-back's lack of game time is expected to result in Munster's Felix Jones coming on to the bench.
Mike Ross returned to training yesterday and assistant coach Les Kiss expects the tighthead prop to hit the ground running against South Africa, despite being out for more than a month since injuring his groin against Munster.
"The truth is he has got to front up for us and that is all there is to it," the Australian said. "That's putting in as many minutes as he can.
"We just haven't had the opportunity to give him the game time and he has done a fair bit of training, that is for sure, to work as hard as he can. You just have to bank that that is good enough.
"He has got one game to get into it this time and it's a big one. That is all there is to it."
And Kiss says Ireland will not use their lengthy injury list as an excuse as they prepare to face the No 2 side in the world.
"What we don't have we can't look at and we go back to what we have," he said.
"We do have a good, strong core. By no stretch of the imagination are we lying down.
"We have had some good intense sessions. The players themselves have really stepped up to the mark in terms of their own voice in training and in meetings to say this is an opportunity for us to step up to the plate, make something happen and do something good.
"We are on our home turf for a start. South Africa travel, albeit from a very successful campaign in the Rugby Championship.
"They set up camp for about a week and a half before they got here. They are well prepped but we have just got to back ourselves in the situation. We have a great group of players."
South Africa have ruled Ulster scrum-half Ruan Pienaar out for their entire November campaign and have called up Toulouse's Jano Vermaak as a replacement.