Big-spending French club Montpellier are willing to test the IRFU's resolve by offering CJ Stander a lucrative move to the Top 14.
Backed by billionaire Mohed Altrad and coached by Vern Cotter, the French heavyweights are understood to have identified the Irish back-row as a target and are hoping to tempt him away from Munster.
The 27-year-old is now considered a greater flight risk than Peter O'Mahony, who looks increasingly likely to remain in Ireland.
The union's initial offer to Stander is believed to have fallen well short of what was expected.
Negotiations are continuing back and forth between the player's representatives and IRFU chief David Nucifora, but the presence of a big offer from Montpellier is muddying the waters.
Stander joined Munster in 2013 and qualified to play for Ireland three years later. He has been a fixture in Joe Schmidt's team since, earning a spot on the Lions tour last June and coming off the bench in the final Test against the All Blacks.
He has captained his province in O'Mahony's absence and has been a pivotal member of their side and a massive fans' favourite.
His connection with the province, initial commitment in moving to Ireland and desire to play at the 2019 World Cup for his adopted country, could prove strong enough to keep the French side at bay should the union come up with a competitive offer.
Meanwhile, Joey Carbery has brushed off Eddie O'Sullivan's suggestion that he should leave Leinster for another province to get more game time at out-half.
The former Ireland head coach insisted that the 22-year-old - who is targeting a January return - would be better elsewhere ahead of the World Cup but Carbery has no intention of going anywhere.
"I didn't think too much of it to be honest," Carbery said. "The opinions that really count are in the actual environment. I think it's the best environment to be learning in, behind Johnny (Sexton) and Rob (Kearney). I'm learning as much as I can in Leinster as I would anywhere."
Subscribe to The Left Wing, Independent.ie's Rugby podcast, with Luke Fitzgerald and Will Slattery for the best discussion and analysis each week. From in depth interviews with some of Irish rugby's biggest stars to unmatched insights into the provinces and the national team, The Left Wing has all your rugby needs covered.