Rangnick, who takes charge of his first game as Manchester United boss later today against Crystal Palace, is looking to add to his backroom staff.
He is expected to appoint an assistant and the Red Devils have been linked with current New York Red Bulls coach Gerhard Struber.
However, RB Leipzig have just sacked Marsch following a poor season so far for the club and Fjortoft thinks he could be a potential assistant for Rangnick.
Marsch worked as assistant to Rangnick at RB Leipzig in the 2018/19 season and is aware of the way the new Manchester United boss likes to work.
Fjortoft wrote on Twitter: “He has worked closely with Rangnick before!
“Could he come to Manchester United as an assistant?”
It remains to be seen whether Marsch would want to jump straight back into the game after being sacked by RB Leipzig, but an opportunity to head to Manchester United would likely give him much to consider.
