Rosicky spent five years with Dortmund after joining from Sparta Prague in 2001 and quickly became a favourite with BVB fans.
Reus has insisted that Rosicky would have been one of the world's best players if persistent injuries had not blighted his career since joining Arsenal.
He told The Guardian: "My idol was always Tomas Rosicky. He used to be phenomenal.
"He had such a good eye for an opening and knew where his team-mates were, and he was so quick. Rosicky had great technique and was so intelligent and mature even though he was still young at Dortmund.
"I copied everything about him, right down to his sweatbands. He was so unlucky he had bad injuries at Arsenal because, otherwise, he would be one of the world's best players."
The 23-year-old has scored 13 goals in his first full season since joining Jurgen Klopp's side from Borussia Monchengladbach.