"I would like to thank all the fans who have been brilliant to me over the past two seasons and I've had a great time at the club," he told the official website.
"It's one of the closest and highest quality squads I have ever worked with and the gaffer (Paul Lambert) and 'Cully' (Ian Culverhouse) are two of the best managers I've ever worked with as well.
"But I already had made my decision up regardless and it was time to move on. The way Port Vale have conducted themselves has been very professional and that was credit to Steve (Port Vale Scout) and Lee Sinnot the manager."