Klose scored 71 times for Germany in 131 appearances, winning the 2006 World Cup Golden Boot and finishing runner-up in 2002. At club level he played for Kaiserslautern, Werder Bremen and Bayern Munich.
The World Cup's all-time top scorer is now a coach with the Germany national side under Joachim Low, but could have joined Tuchel's staff a year earlier.
"I talked over football during time alone with Thomas Tuchel, and Dortmund wanted to oblige me in 2015," Klose told Kicker.
However, he has not ruled out a return to the Bundesliga, and admits he would one day love to manage in the German top-flight.
"Of course you want to coach in the Bundesliga when you move into coaching," Klose said.
"The Bundesliga must be the goal, and it is my goal."