Chelsea are said to have a good chance of keeping Ian Maatsen this summer.
The Stamford Bridge club are considering whether they should be selling the left-back after he impressed on loan at Borussia Dortmund.
Per Sky Sports Germany, Dortmund want to sign Maatsen, but for less than his release clause.
They can secure him anytime for 35 million, but want to negotiate down that fee.
The source adds that if a 21.3 million bid comes in from Dortmund, Chelsea are likely to reject it.
The club may choose to retain the 22-year-old, who has helped Dortmund reach the Champions League final.
The German giants also want to sign Jadon Sancho permanently from Manchester United.