The Red Devils had an £89m offer rejected for the 20-year-old England international yesterday.
The Bundesliga side are holding out for £21m more – a figure that far exceeds United’s valuation.
And The Telegraph report the Premier League club will refuse to pay that much but remain confident that an agreement will be reached.
Dortmund return to pre-season training on August 10 and hope to have Sancho’s situation sorted by then.
However, United “will not be forced into meeting some arbitrary deadline” by the German outfit.
