It has been reported that Atletico Madrid are interested in signing the Slovenian, who joined Leverkusen from Borussia Dortmund at the start of the season.
"What applies to Chicharito (Javier Hernandez) and Christoph Kramer is the same for Kampl. We're not going to let anyone go," he told Bild. "It's definitely not an issue. Kevin is delighted with us and we are happy with him. We need the player."
Kampl, 25, has scored twice in 24 appearances for his German club this season.