LEIPZIG, Germany — A little more than three years ago, the man in charge of the most ambitious project in European soccer sat in front of a promising young player in a Cypriot hotel and told him the future.

At the time, the man, Ralf Rangnick, a well-traveled German coach with an urbane, faintly academic air, seemed an unlikely clairvoyant. And his pitch to Yussuf Poulsen, a young Danish forward, did not seem to be a strong one. Rangnick’s club, RB Leipzig, was attempting to escape the fourth tier of German soccer. It did not have a famous name, or much of a history. His predictions, too, struck Poulsen as distinctly outlandish: promotion all the way to a place among Germany’s elite in just three seasons.

“He said this club was the club of the future,” Poulsen recalled last week.

Poulsen signed on, and the rapid ascent Rangnick had laid out in the hotel — a romantic rise or a cash-fueled corporate push, depending on one’s point of view — continued.