Martin O’Neill has called on UEFA to act over the Danish dispute which threatens to turn the Republic of Ireland’s Nations League group into a farce.

Denmark’s preparations for their opening game in the competition against Wales are in turmoil following a dispute between the Danish Football Association and their Players’ Association.

It could lead to Denmark fielding a scratch side of third-tier and indoor futsal players in Aarhus on Sunday, rather than established performers such as Tottenham midfielder Christian Eriksen and Leicester goalkeeper Kasper Schmeichel.

Danish FA bosses have said negotiations to resolve the dispute over the players’ commercial rights will restart after the Wales game, so it is not inconceivable that the Republic could play a full-strength Denmark side in Dublin next month.

“If it does develop this way there would certainly be a degree of unfairness about it,” manager O’Neill said at his press conference ahead of the Republic’s opening Nations League tie against Wales in Cardiff on Thursday.

“I think everyone would accept that if Denmark play players from lower divisions against Wales then it certainly gives them a massive advantage.

“I think UEFA probably should (act), and will as well, if it develops in the direction that it looks as if it is going. UEFA will have to make some sort of statement about it then.

“It wouldn’t be fantastic news for the competition itself, but we have to see if things get resolved in the next couple of days and Denmark play their full-strength side.”

The Republic’s troubled build-up to the fixture suffered another blow when Preston midfielder Alan Browne was ruled out by a calf strain.

Browne joins James McClean, Robbie Brady, James McCarthy, Scott Hogan and Shane Long on the casualty list.

Bournemouth midfielder Harry Arter withdrew from the squad following a spat with assistant manager Roy Keane, while West Ham defender Declan Rice made himself unavailable as he considers switching allegiance to England.

O’Neill said: “Whatever goes on with some of the players at club level, whether they’re playing or not, they come in and get themselves prepared for the game.

“Whatever we have we will just give everything we possibly can during the course of the match. The players have done that before my time and during it as well.”

O’Neill will be taking charge of his 50th game as Republic manager in Cardiff and believes the new Nations League is a step forward for European football.

“The competition has a bearing on the European Championships later on,” he said.

“Despite the fact that there seems to be a feeling that no-one totally understands what it’s about, I think we’ve got the gist of it.

“If you pare it down this competition has taken the place of a play-off situation for some third-placed teams, so I think it is really important.”