Since his arrival at the club in 2015, Dallas has been awarded three Player of the Season awards, helped the Whites achieve promotion to the top flight, and transformed into a quality Premier League player.
Under Marcelo Bielsa, Dallas has become undroppable, with the 30-year-old playing all but nine minutes of the Whites’ impressive first season back in the Premier League.
But it has not all been plain sailing for Dallas, who has also suffered the disappointment of several failed promotion bids during his time at Elland Road.
“In sport, when things are going well and you’re winning, everything’s great,” Dallas said.
“When you get a defeat, your wife and kids are the ones that pick up the pieces.
“I think a lot of people think that when you play and you maybe get beat, people think, ‘oh it’s all right, they’re getting so much money that you don’t care’. But it’s not like that.
“You go home and you’re constantly playing the game over and over in your head and you’re taking your frustrations and your emotions on your wife and she’s the one who’s there to pick it up and deal with it.
“For me, it’s a very very important role that she and the kids play.”
Earlier this year, Dallas spoke at length about how a network of support, including his family and team-mates, was essential to getting through a tough period of bereavement.
The Ulsterman pulled out of Ian Barraclough’s Northern Ireland squad in September after a close friend passed away.
Dallas missed out on World Cup qualifiers against Lithuania, Estonia and Switzerland but was immediately involved for the Whites again at the end of the international break.
Eleven days after withdrawing from international duty, the 30-year-old started in the Whites’ 3-0 defeat to Liverpool, later explaining that he didn’t want to ‘let anybody down’. But his own dedication comes at personal cost to those around him, Dallas revealed in Carl Frampton’s A Different League podcast this week.
“You probably become a bit selfish because your career is so short but everything sort of has to revolve around you,” Dallas said.
“Whenever I’m here training, my missus is doing everything with the kids.
“They’re on this rollercoaster - the sports journey is an unbelievable journey of unbelievable highs and unbelievable lows.”
Now one of the Whites’ longest-serving players, Dallas has become a hero to the Elland Road faithful, revered for thriving in a wide range of positions and covering great distances on the pitch.
Last season, he stunned fans by scoring the brace with which 10-man Leeds dispatched title-holders Manchester City in an unlikely 2-1 victory.
Two years previously, a Dallas double was followed by one of the club’s all-time lows as Derby County came from behind to crush Leeds’ promotion hopes in the 2019 play-off semi-final.
When the Whites sealed top-flight status the following season, there was one person for whose support and contribution Dallas was especially grateful.
“The first thing I did when we got promoted was phone my wife to thank her,” Dallas said.
“It’s not easy being at home with three kids and doing everything and not being able to do what her career has had to go on hold while I pursue mine.
“When I’m finished in a few years’ time maybe she can go on to do something that she loves.”