Dallas has been rubbing shoulders with the likes of Robert Lewandowski, Thomas Muller and Gareth Bale in France over the past few weeks but it was not so long ago that life looked very different.
In 2012 he was plying his trade with Belfast outfit Crusaders, earning £70 a week, training when he could and holding down permanent employment during the week.
His first taste of professional football came when Brentford took a chance on him four years ago, and he impressed enough at Griffin Park to earn a move to Leeds and a place in the national set-up.
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Like the rest of his team-mates, 25-year-old Dallas was downcast after Saturday's last-16 defeat by Wales, but he also sees a silver lining.
There are concerns over the number of young Northern Irish players making the move across the water at present, crowded out by the far-flung scouting networks in England, but youngsters back home could hardly fail to be stirred by Dallas' recent achievements.
"Hopefully if I can inspire young lads from back home to believe in themselves and if I've shown them anything is possible then that's great," he told Press Association Sport.
"I was that lad once, not so long ago: happy at home, playing with my mates, working a full-time job and I took the risk of coming over to England.
"There's a lot of hard work goes into what has happened since but that was the best decision of my life.
"There's a lot of very good young players at home and hopefully they can get the break that some of them need."
Dallas has known only good things since returning to the Northern Ireland squad in early 2015.
He played an important role in helping the side seal their first ever appearance at a European Championship, was key to their 12-match unbeaten streak and helped them defy the odds to qualify from a testing group.
But on Saturday night in Paris, he had new emotions to deal with.
"It's hard to take, the emotions were raw," he said of the post-match atmosphere.
"The feeling in the dressing room was just disappointment. Obviously we've achieved a lot to get here but we always said we weren't here to make up the numbers.
"I don't think anyone was sitting there thinking about what we've achieved. We were upset to lose the game.
"People wrote us off saying we wouldn't get out of the group but we proved them wrong. We could have gone out having not turned up at all and that would have been worse, we would have had regrets then.
"But everybody gave everything they had on that pitch and, although I don't think we got what we deserved, we had no regrets."