Kingsley Coman has endured a difficult year due to ankle injuries and another recurrence could see him call it quits.
Bayern Munich hold an interest in Frenkie de Jong, who has been heavily inked with a move to Paris Saint-Germain.
After scoring the winner for Borussia Dortmund away to Bundesliga rivals Schalke, Jadon Sancho dedicated the goal to his late grandmother.
Champions Bayern Munich beat Nurnberg 3-0 on Saturday, but remain nine points adrift of Bundesliga leaders Borussia Dortmund.
Bayern Munich moved into second place in the Bundesliga by hammering Bavarian rivals Nurnberg 3-0.
Teenage sensation Jadon Sancho settled the first Revierderby of the season with the winning goal in a 2-1 victory for Borussia Dortmund.
England winger Jadon Sancho has become one of the hottest properties in Europe this season, but Borussia Dortmund insist he is not for sale.
Ousmane Dembele has had a turbulent time at Barcelona, and Michael Zorc is relieved because it means Borussia Dortmund are not to blame.
Less than two minutes into his Bundesliga debut for Werder Bremen, United States teenager Josh Sargent scored.