The Norway international is in high demand after netting 49 goals in 51 appearances for Dortmund, attracting interest from the likes of Barcelona, Real Madrid, Paris Saint-Germain, Manchester City and Manchester United.
Talk of a transfer intensified after Haaland's agent, Mino Raiola, was said to have been in contact with a number of clubs, having reportedly spoken with representatives from Barca and Madrid.
But Zorc, who is eager to keep hold of the 20-year-old, claimed the Bundesliga club would not be rushed into a panic move.
"I don't see the need to set deadlines at the moment [for transfers]," he said on Thursday.
"Yesterday I spoke to Mino Raiola. We've made our intentions very clear. It's no problem when Alfie [Haaland's father] and Mino want to take a sunbathe on the Mediterranean Sea.
"I am relaxed because I know what we want."