Davies made no secret of his desire to play in the Premier League again.
"Of course it was inevitable, 100 per cent," Clark told the Birmingham Mail.
"As a manager, with my selfish hat on, it was not one I wanted to happen.
"I wanted to build this young, hungry squad around Curtis with him being the leader.
"For a couple of reasons, one being the finances at the club and the other being Curtis wanting to sample Premier League football again, this is why he has gone.
"What people inside the club have had to do is negotiate the best deal possible.
"That's what they have achieved, really, in terms of Hull. We accepted their offer and Curtis agreed his terms.
"Of course it is a blow when you have lost a player of his ability. I have always said he is a Premier League player. But we just have to deal with it and move on."