The Blues’ hunt for the Croatian star has been one of the summer’s longest-running transfer sagas.
“Most clubs don't want to talk about players they are interested in but the Modric situation became public,” Buck said.
“We did make an offer, Daniel Levy has rejected that offer and I don't know if it will go any further, we will have to see.”
"The club's position on Luka Modric is quite clear," he said. "We have no intention of selling him."