Manchester United are reportedly hopeful of signing Jadon Sancho in time for their 2020-21 Premier League opener against Crystal Palace on September 19.
BVB have insisted on a number of occasions that United have missed the deadline to sign the England international, but the transfer window is still open until early October.
The 20-year-old would need to be registered as a United player by 12pm on the Friday before the match in order for him to be eligible to take to the field against Roy Hodgson's side.
The Red Devils are believed to have made strong progress in their discussions with Sancho's agents, although Dortmund are still said to be unprepared to drop their £108m asking price.
United's participation in the latter stages of the Europa League means that they have been given an extra week to recover before beginning their domestic campaign.