Northern Ireland were beaten 1-0 by Wales after a cruel second-half own goal by Gareth McAuley saw Wales reach the quarter-finals and sent Michael O’Neill’s side home.
Despite the heartache, Dallas can now reflect on the progression of his career. In 2012 he was plying his trade with Belfast outfit Crusaders, earning £70 a week 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 to earn a move to Leeds and a place in the national set-up.
“It’s hard to take, the emotions were raw,” he said after Saturday’s defeat.
“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. 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.”
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.”