Now Michael Preetz, general manager of the Bundesliga outfit, has spoken about the speculation surrounding Kalou's future.
Preetz insists the Ivory Coast front man is staying at the club, and dismissed the suggestion that he could end up at Pride Park.
“Salomon was our top scorer last season," he told Kicker. “He is staying here - we are planning with him.
“With all due respect to Derby County , while it is realistic Salomon will be keen on a new challenge at some stage, it's hardly going to be the English second division, even if Lampard and Sala respect each other from Chelsea."