"I said four to six weeks ago that at the end of the season I would make a decision on my future and I definitely want to leave," said the striker who has been at the club for six years.
"The circumstances that I have to go in leave me a bit upset. I never wanted to leave under these circumstances, but I did actually ask to leave at the beginning of the season and the request was turned down.
"I asked again in January and it didn't happen then. I have had six fantastic years here, the last two have not been as good as the other four, but I just think it is time for me to move on.
"I have become a bit stale and I need a fresh challenge. It looks like I will be leaving and for me personally, it's an exciting time."