The England international will be a Reds player next season but Storrie says it was in the player's best interests to make a move.
"How can you question the sale of a player to a club with Champions League football on offer? Storrie told The News.
"But when a top-four club with Champions League football comes knocking it is very, very difficult.
"When he signed his new contract he asked us if we would give him permission to talk to a Champions League club if they should come in for him.
"This was a verbal agreement and we have honoured that. That has nothing to do with our ambition as a club."