Dortmund recently insisted that the 20-year-old would not be leaving Signal Iduna Park this summer, and the former Manchester City youngster was involved in the German club's first pre-season friendly ahead of next season on Wednesday.
According to the Daily Mail, United are not prepared to meet Sancho's £108m asking price, while their approach to contract talks has also brought about some confusion.
The report claims that the Red Devils first proposed a deal which would have seen the England international take a pay cut, while the second would only have matched his current £190,000-a-week wages.
The onus is allegedly on United to 'resurrect the situation' as Dortmund are determined to keep hold of the attacker unless their valuation is met before the start of the 2020-21 campaign.
Sancho enjoyed an excellent 2019-20 season for BVB, scoring 20 times and registering 20 assists in 44 appearances in all competitions, including 17 goals and 17 assists in the Bundesliga.