The German international returns to Borussia Monchengladbach today for the first time since his summer move to Dortmund, where he has gone from strength to strength.
"In my career I have certainly learned to most from Lucien Favre," Reus told Bild.
"He has supported and shaped me, and worked with me on many scary details. I will never forget that."
The coach was equally complimentary about his former player.
"Marco is the best player I've worked with," Favre said. "It is very difficult to stop him, but we must not make the mistake of only focusing on Reus."
Reus has scored 12 times for Dortmund this season, including two against his former club in September.