Brian O'Driscoll feels it will be just one of Quinn Roux or Ultan Dillane that make it into Ireland's Rugby World Cup squad.
Both will start the third 2019 Six Nations game against Italy. Currently, the second-row pecking order has James Ryan, Devin Toner and Iain Henderson leading the way.
With the versatile Tadhg Beirne also an option, it means only one of the Connacht team-mates is likely to travel to Japan.
Speaking on Off The Ball, BOD gave his thoughts on how that second row battle will play out.
"If you're talking about the three second rows and you're picking from a full deck, you're looking at Ryan No 1, Toner No 2 and Henderson as No 3," he said.
"Then, do you pick a Tadhg Beirne who can play in the back-row and the second row? That would mean only one of those two will get to go.
"You're only going to see four second rows. But are you going to pick four out-and-out second rows? And even in that case, only one of them will go.
"So is there an outside chance that both of them don't go? Yeah, but the fact that Tadhg Beirne is fit and not getting game-time, I think really spells it out that one of these two are going to be the guys who will be selected for Japan."
BOD also ran the rule over the Ireland team which is a mix of experience and fringe players.
"It's nicely mixed up. Four changes obviously and a long over-due rest for a couple of players," he said.
"Particularly, the likes of Rory Best who doesn't need those extra miles on the clock. Also conversely from an age perspective, James Ryan was badly due a rest as well. He's played a lot of minutes and he's an 80 minute guy."