The Leeds summer signing has a lot to thank the German for.
Indeed, Rosler was an understanding manager when the 24-year-old made the transition from part-time football to full-time playing at Brentford.
And that experience leaves Dallas very much looking forward to working under the German again in Yorkshire.
Dallas told BBC Radio Leeds: "It's always a good thing whenever there's a manager who knows what he's getting from you. I know what I'm going to get from him, as well. He had a big part to play in me coming here.
"I enjoyed working under him at Brentford. He brought me in and he blended me in well. I was coming in from part-time football and he didn't throw me in at the deep end. It took me a year and a half to get going and I enjoyed my time under Uwe."
Dallas or Doukara?
Right now, it seems as though it's a straight choice between summer signing Dallas or Souleymane Doukara for the left-wing slot against Burnley on Saturday afternoon.
Both Leeds stars have drawbacks when it comes to Rosler selecting them - the fact Dallas is new to the squad and doesn't need to be thrown in 'at the deep end,' as he says, as well as the fact Doukara heavily flattered to deceive last season in the Championship.
At the same time, though, both have obvious qualities that stake their claim for a starting spot. Dallas was brought to Elland Road to fill a void out wide, while Doukara was kept at Leeds as he clearly did enough during pre-season. Who would you choose?