Josip Drmic has been linked with a Bayer Leverkusen exit. Fabrice Coffrini/AFP/Getty Images

Bayer Leverkusen are not willing to sell Josip Drmic to Hamburg, according to sporting director Rudi Voller.

Last summer, Drmic, 22, joined Leverkusen from Nurnberg, where his 17 goals in his maiden Bundesliga season were not enough to help the club remain in the division.

However, after his seven million-euro transfer to Leverkusen, the Switzerland international has found it difficult to adjust to the new challenge. While making 21 appearances for the club in all competitions, he has started only four and found the back of the net just three times.

Those difficulties have led to speculation that the attacker could be on his way out of Leverkusen after only six months, with Hamburg -- who struck only nine goals in their first 17 matches of the season -- emerging as the favourites.

"Should our club boss Dietmar Beiersdorfer tell me that it's going to be Drmic, I would say yes," Hamburg coach Joe Zinnbauer said in Bild.

Drmic, however, told kicker: "That's not news that Hamburg are interested. But I don't want to discuss it. I am here in Orlando, I am in the [Leverkusen] training camp and I am fully focused."

Drmic did admit that he is not happy with his current situation.

"No player is happy when he's not playing," he said. "I envisaged it differently, that's clear. Everyone knows that."

Voller, though, insisted that Drmic will not be sold nor sent out to another club on loan.

"Both are out of the question, we won't do it," Voller told Bild, before backing the Switzerland international to succeed at Leverkusen. "He will play an important role for Bayer in the future."

Leverkusen squad manager Jonas Boldt added in kicker: "We won't give him away."