In Dortmund’s negotiations with United, they previously set a ‘deadline’ of 10 August for the deal to be completed for the former Man City youngster.
After that deadline went by, Dortmund sporting director Michael Zorc insisted on Monday no deal would be struck.
"We plan on having Jadon Sancho in our team this season, the decision is final. I think that answers all our questions," Zorc told the media.
“Last summer, we adjusted Jadon's salary to match the development of his performances. So in context, we had already extended his contract until 2023 back then."
It is believed that the Red Devils remain undeterred by this statement from Zorc and believe that a deal can still be finalised.
But, if the Bundesliga side remain stubborn with their current position, they have identified two alternatives.
Coman is one, with the Frenchman likely to go down the pecking order at the Allianz Arena following Bayern’s big money signing of Leroy Sane from Man City.
Sancho remains Ole Gunnar Solskjaer’s top priority, however.