Borussia Dortmund sporting director Michael Zorc has claimed that the Bundesliga club cannot afford to replace striker Robert Lewandowski.
Dortmund revealed on Thursday that the Poland international, who has been linked with Bayern Munich and Manchester United recently, will not be signing a new deal with the club in the summer.
Zorc has said that bringing in a player of similar ability to Lewandowski is unrealistic.
"Economically, that's not imaginable for Borussia Dortmund," he told Kicker.
"We would need to sign an absolute world-class player to match the quality Robert Lewandowski embodied in the three years he's been playing for us."
Lewandowski has hit 21 goals in 32 appearances for Dortmund this season.