Monchengladbach announced Rose's departure on Monday, with Dortmund yet to have confirmed his appointment. Rose's role with the Black & Yellows was not clarified but he is widely expected to be named the club's new head coach.
Edin Terzic was appointed as Dortmund's interim boss in December following the sacking of Lucien Favre, but after a promising start is now also failing to get the best out of the group of players at Signal Iduna Park.
With only one league win in their last six matches, they have fallen out of the Champions League places, with Saturday's draw at home to Hoffenheim leaving them six points behind Wolfsburg in fourth - and 15 points off top of the table Bayern Munich.
Gladbach announce departure
"We have held a lot of talks in recent weeks to discuss Marco's future," Monchengladbach sporting director Max Eberl said.
"Unfortunately, he has now decided that he would like to make use of a clause in his contract, which runs until June 2022, to switch to Borussia Dortmund in the summer.
"If the conditions stipulated in his contract are met on time, he will no longer be available to us after the end of the season.
"Until then, we and Marco will mobilise all of our strengths to achieve our goals in the Bundesliga, the DFB Cup and the Champions League."
The two teams are currently level on points in the Bundesliga, with Dortmund holding sixth-place by virtue of a superior goal difference.
Gladbach have also been drawn at home to Dortmund in the quarter-finals of the DFB Cup on March 2 and will face Manchester City in the last-16 of the Champions League.
Making his mark
Rose, 44, joined Gladbach from Red Bull Salzburg in July 2019 and has won 36, drawn 18 and lost 18 of his 72 matches in charge.
Playing out the end of his career under the tutelage of Jurgen Klopp at Mainz, it’s perhaps not surprising that Rose fitted in well with the Red Bull house style.
Quick, energetic, direct attacking football brought Rose back-to-back league titles at Salzburg and has Gladbach scrapping it out at the top end of the table in Germany.
Attacking playing style
“The basic ideas behind my playing philosophy are emotionality, hunger and being active,” he explains. “We want to be very active against the ball, sprint a lot. We want to win high balls and have short ways to the goal.
"We don’t want to play high and wide, but fast, dynamic and actively forward. This all sounds really awesome, but it’s gonna take time to develop these things.”
Rose utilised a 4-4-2 diamond at Salzburg and has expressed his preference for it: “I’ve always played a diamond when I’ve had the opportunity to do it, bringing in two strikers. Our system, even when we play with all three up front, is something like a diamond.”
He guided Gladbach to a fourth-place finish in the Bundesliga last season and they impressively negotiated a Champions League group stage featuring Real Madrid, Inter Milan and Shakhtar Donetsk this term.