One of the question marks hanging over Albion in the Premier League is their shortage of top level experience.

How will the players cope with the kind of quality they will be facing week in, week out?

It is hard to know until you have been challenged in such an exalted environment.

So Shane Duffy will be a reassuring presence at the heart of the defence.

The formidable figure from Derry, still only 25, has played in the Premier League before for Everton.

That was a while ago and much has changed. Of far greater relevance is Duffy's role with the Republic of Ireland.

He has established himself as a key member of the rearguard action when Martin O'Neill's side confront some of the best teams on the international stage.

It has not always been a smooth ride, as Duffy's former Everton colleague turned opening day rival with Manchester City, John Stones, has also discovered.

There are bound to be bumps along the way as a young defender trying to deal with the most lethal strikers in the global game.

The Argus: In the last 16 of the Euro finals in France last summer, when Duffy was still with Blackburn Rovers, he was sent-off for bringing down Antoine Griezmann (above).

He will face the Atletico Madrid marksman again in Sunday's showpiece friendly at the Amex, a little bit wiser and better prepared for the tasks ahead of Albion over the next ten months.

Especially as Duffy regards the examination awaiting the Seagulls as one not dissimilar to that regularly encountered by the Republic.

Duffy said: "You are playing against those type of players and you think 'Okay, it's not that much of a gap'.

"Ireland in a way are similar to Brighton. We have a good shape and we're hard to break down against the Germans and top teams.

"Physically it's the same. You are playing against world class strikers. It's just every week now, not every couple of months.

"I think it's going to help me. In the Euros, playing against France and Italy, they had players in the champions League and we did allright.

"The Premier League is a whole different world. You don't know until you are tested in it.

"I've got big tournament experience and it could help me in the big games, not being so nervous. I've played in the last 16 of the Euros.

"I know I can play against those calibre of players, it's just doing it consistently in the best league in the world."

Duffy has become increasingly important to O'Neill's quest to qualify the Irish for the World Cup finals in Russia next summer.

He came straight back into the side from injury and a had a late goal disallowed in the 1-1 draw against Austria in Dublin in June.

Albion manager and former Republic of Ireland defender Chris Hughton's survival strategy for the Premier League will centre around Duffy's commanding partnership with Lewis Dunk.

It was the bedrock for promotion from the Championship until Duffy, bought for around £3.5 million from Blackburn last August, fractured a metatarsal at Nottingham Forest in March (below), which ruled him out of the run-in.

The Argus: "It was frustrating personally but we were winning and I was delighted," he said. "I know I played a good part in the season. It was out of my hands then.

"As soon as I got my head around it, it was just the same feeling when we were winning. How could you be disappointed? I was delighted for the team."

They have taken Duffy back into the Premier League. It will, nevertheless, effectively be a new experience.

The financial climate - and playing styles - were a contrast with the present when Duffy had a run of games as a 21-year-old under David Moyes at Everton.

"It's a lot different now," he said. "The money in it is ridiculous. We are all looking at City, because it's the first game, and what they are spending on full-backs.

"That's what we are up against now. Back then £30 million was massive. That's cheap now.

"It's a different game as well. When I was at Everton it was a lot more physical and the team I was in under David Moyes was a lot more physical.

"It was more like 'get it up to the big man and play off him'.

"I'm looking forward to it. It's going to be a good challenge for all of us."