The club had long been planning a similar spectacular — for the weekend of March 14-15 — but those plans are now in jeopardy.
"I'm scratching my head that we could be in this situation — I find it extraordinary," Warriors co-owner Eric Watson told the Herald on Sunday. "I'm hoping there is some rational explanation along the way but we need to work out what the options are for the club."
Watson confirmed legal advice had been sought and the club was investigating all options.
"We will have to work our way through it," said Watson. "It's a pretty big issue. Our rights as principal tenants have definitely been contravened. I'm not quite sure how it is going to be resolved. There is a lot of value at stake."
Warriors chairman Bill Wavish said: "It's a very serious breach of contract and it is going to take some time to resolve."
Eden Park is unavailable on the date due to the Cricket World Cup and the Herald on Sunday understands that any legal action could seek compensation for breach of contract, or look to move the Eagles concert to another location.
The concert could take Mt Smart Stadium out of commission for at least two weeks. Large-scale stage shows, such as those by U2, Bruce Springsteen and the Eagles, usually take at least a week to prepare, including converting the ground, installing extra seating and the stage.
Time is also needed to convert the stadium back to a league ground, and there are concerns about the impact on the playing surface.
Round two was earmarked for the Broncos match as the Brisbane side traditionally opens its season at home. The NRL is keen to maximise television audiences in round one.
Regional Facilities Auckland, the Auckland Council agency that runs major venues around the city, said the NRL was told about the concert.
Spokesman Paul Brewer said the RFA did not believe it was in breach of its arrangements with the Warriors.
"We have given them 10 months' notice," he said. "The NRL are very experienced at working fixtures around prior commitments. We don't anticipate it will cause any difficulties."
Paul Nisbet, director of stadium management for RFA, said the venue would be "clear of all concert production infrastructure and equipment to allow any Warriors game at Mt Smart for round [three]".
He also said steps would be taken to protect the playing surface.