Lucien Favre has acknowledged that Borussia Dortmund have a better chance of success with Jadon Sancho in their side.
Having starred for the Bundesliga outfit last season, Sancho is wanted by Manchester United, who remain keen to get a deal over the line before the end of the summer transfer window.
However, the Premier League giants are refusing to meet Dortmund's asking price, said to be set at £108m with the player having three years left on his contract.
When quizzed on the England international's future, Favre has suggested that there is no chance of the 20-year-old leaving the Westfalenstadion.
Speaking to SDS, Favre said: "We need him, no question about it. Everyone was happy that he stayed. We don't need to talk long about his qualities - they are enormous. He scores and prepares many goals, can often make all the difference.
"But there are a few details that Sancho needs to improve. That's normal for a 20-year-old."
Sancho has contributed 34 goals and 43 assists from his 99 appearances for Dortmund.