Michael O'Neill's men have been handed a huge selection dilemma after starting left-back Chris Brunt was ruled out of Euro 2016.
The 31-year-old went, ironically, to Lyon - the venue of the Green and White Army's second group game against Ukraine - to have reconstructive knee surgery.
Brunt will now be out for around six months and faces a race to be fit for the start of the new season with West Bromwich Albion.
The experienced midfielder, who had been molded into a defender, has 51 caps and one goal for his country.
He missed just two games during Northern Ireland's qualification campaign, as they topped Group F ahead of Romania to book their place in the finals.
Not only will Brunt miss the nation's first major tournament for 30 years and their first ever European Championship appearance, but it could be his last chance to do so.
Speaking on the news, manager O'Neill said he was "devastated" that Brunt would be missing out and insisted "the team will support [Brunt]" through the recovery period.
Baggies boss Tony Pulis also had his say to the club website, "It’s a big blow for Chris and everyone is feeling for him right now.”
He added, “It will be disappointing for us not to have him for the rest of the season because he is a terrific player who gives the team great balance."
Who will take his place?
The natural replacement for Brunt would be Millwall's Shane Ferguson, who was brought on at left-back during the qualification period.
While Ferguson offers more of an attack outlet, it may be that Craig Cathcart is drafted in to play in an unfamiliar role to give added defensive stability.
Perhaps Daniel Lafferty could make an unlikely return to the international fold, but Ferguson should get the nod to star in France.