Leverkusen have revealed that they have fielded several enquiries for playmaker Hakan Calhanoglu from clubs across Europe.
The 21-year-old is considered on of the best young talents in European football and his stock has soared following several good performances this season.
The likes of Barcelona and Atletico Madrid have reportedly enquired over the Turkish star, while Manchester United have regularly scouted him.
Leverkusen sporting director Rudi Voller confirmed that the club have been asked about Calhanoglu's availability, but insists he is not for sale.
"It is true that we had several enquiries, but we did not want to sell the player, which would weaken us," he told Sport Bild.
Club CEO Michael Schade echoed Voller's sentiments, but claims that he is not concerned about the growing interest in the player.
"We want to keep Hakan, but there is an absolute limit," Schade added. "I am relaxed about [the situation]."