Should Casey have been given more of a chance?
However, the youngster has only ever made three appearances for the senior side, and with a number of centre-backs ahead of him in the pecking order, he has decided to seek first-team football elsewhere.
Leeds fans flocked to the tweet from the official club Twitter account sharing the news of his departure and it was apparent some were not impressed with the defender leaving.
What exactly did these Leeds fans have to say?
“This isn’t what we meant when we said we wanted transfer news”
Casey joins Blackpool, who were recently promoted to the second tier after beating Lincoln City in the final of the League One play-offs.
Going by the reaction of these Leeds fans, it seems apparent some of them were not too keen on this piece of transfer news, with many feeling he was one to watch for the future.