Jadon Sancho should stay at Borussia Dortmund for "one or two seasons longer" as the club is the right place for his development, says Jorg Heinrich.
Sancho has shot to stardom since leaving Manchester City for Dortmund in 2017, scoring 12 goals and supplying 14 assists in 34 Bundesliga appearances last season.
The England forward has continued to shine in the new campaign with three goals and a league-high five assists to his name despite Dortmund's inconsistent form.
A Premier League return has been mooted for the 19-year-old, with Manchester United among the clubs reportedly interested in signing Sancho.
However, Heinrich, who won two Bundesliga titles and the Champions League as a Dortmund player, believes BVB remains the best club for Sancho.
"Jadon can become one of the best players in Europe, or even the world," Heinrich told Omnisport.
"It won't be easy to keep him at Dortmund. We hope he plays one or two seasons longer but we all know very, very big clubs with a lot of money want to have him in their team.
"He should know Dortmund is an excellent place for young players to play consistently and to develop on a very, very high level."
Dortmund pushed Bayern Munich hard for the Bundesliga title last term but ultimately finished two points behind the Bavarian giants.
The early weeks of the 2019-20 season have been a struggle for BVB, though, with one win in their past five league games.
"Our aims before the season were very, very high," Heinrich added. "We announced we wanted to win the league this year.
"The season so far hasn't gone that well, but we are not that far away from the top, so we are hoping we can fulfil our aims and take the top of the league."
Dortmund's poor form has put Lucien Favre's position in the spotlight, but Heinrich backed the Swiss coach to turn things around.
"No question about that, Lucien is a fantastic coach," Heinrich said.
"We have a great amount of young players and have to show patience with that and trust in our young players and especially our coach."