Jonny Evans' return to the Northern Ireland squad for Monday's clash with Norway at Windsor Park remains uncertain after his surprise withdrawal from the travelling party to Romania.
The Leicester City defender did not travel with the squad for their Uefa Nations League opener in Bucharest tonight, with mystery surrounding his exclusion.
Manager Ian Baraclough, set to take charge of Northern Ireland for the first time, declined to offer an explanation, saying it was a "private matter".
"It's a private matter and it is for personal reasons," said Baraclough.
"We hope when we get back to Belfast, he will be able to join up with the group again.
"But it's a personal matter and I'm not at liberty to elaborate on it."
When quizzed on Evans' availability for the Norway game, he added: "Yeah, we hope so. Yes. Listen, there's never a guarantee, but hopefully he is at the hotel when we get back."
Baraclough is targeting a perfect start after succeeding Michael O'Neill in June but the loss of the 32-year-old former Manchester United ace, who has made 84 appearances for his country, is a significant blow.
Evans, whose debut came against Spain in 2006, has joined Sunderland defender Tom Flanagan in withdrawing from the panel.
"Defensive wise, we've got the likes of Dan Ballard, Conor McLaughlin, Michael Smith and, of course, Craig (Cathcart) is there," added Baraclough.
"We've also got Stuart Dallas, Jamal Lewis and Shane Ferguson, so we've got many good defenders and we've got to make sure we're ready if someone drops out of the squad.
"If we have injuries, there are players ready to come in, and that'll be the case all being well."
Flanagan withdrew last week for personal reasons, with Arsenal's Daniel Ballard called up in his place. The 20-year-old, who played for the Under-21s under Baraclough, was called up by O'Neill for last year's Euro 2020 qualifiers against Estonia and Belarus but is yet to make his senior debut.
This month's games are key preparations for the crucial Euro 2021 play-off semi-final against Bosnia-Herzegovina in October and a potential final at Windsor Park in November.
All games in the September international window will be played behind closed doors, with restrictions remaining in place across Europe to help prevent the further spread of Covid-19.
It’s a first opportunity for the supporters to see a Northern Ireland side fashioned by Baraclough, and the new man in charge has high demands.
“We have spoken about having the right characters in the dressing room,” he added. “That’s top of the list for me. I want a team full of energy and personality and not afraid to express themselves.
“I want them to be a good group together and we’ve had a chat about that. Anyone coming into the squad must be good people. We need everyone pulling in the same direction and respecting our values and ethos.
“We are representing ourselves, the fans and our families.
“The players are aware of how well we want to do in this Nations League and hopefully get a favourable World Cup qualifying draw. The Nations League is the first goal and getting off to a good start is important.”
Romania has struggled to contain the Covid-19 virus but Baraclough is not concerned about the health risk.
“We are not worried about the virus, we wouldn’t be playing these games if Uefa felt players or staff and everyone associated with the game were at risk,” he added.
“We are not afraid or worried, the medical science says it is safe to play. We are mindful of lives being lost in the world but people do want to get back to some sort of normality.
“I hope the games across Europe go ahead safely and we can steer clear of danger.
“If it’s safe to do so, we are pleased to play our part.”
The former Sligo Rovers chief knows he is facing a tough assignment in Bucharest.
“They are strong in midfield and have a team can that can open you up if you aren’t ready and fall asleep,” he said.
“The younger players from the Under-21 set up look good and, of course, they beat England.
“I’m sure it will be a decent game marking the return to international football.
“They have very offensive players, quick in wide areas and I would be surprised if the manager changed his style.”
Like Baraclough, new Romania manager Mirel Radoi was promoted from the Under-21 ranks and is well educated on the country’s emerging talent.
“We never thought we would face each other so soon after being involved with the Under-21s but I’m pleased the associations have promoted from within and I’m delighted to get this opportunity,” added Baraclough.
“Romania can be proud of the next generation coming through, they have great players and I know that from playing against them with the Under-21s.
“Similarly, we have bright young players and they have to show they are good enough to play for the senior side with the experienced players.”