Mr Duffen told The Mail: "Everyone at the club wants to see Deano do what makes him happy and we wish him all the best.
"This is a new adventure that he is embarking on.
"It is a measure of the man that he wants to go out and play football rather than see his time out at a Premier League club.
"He is happiest when he is scoring goals, and we all hope it works out for him."
Deano's video highlights
Deano's legendary Wembley goal
Watch Dean Windass's goal at Wembley and the crowd's reaction as Hull City secured their place in the Premier League
Queen Victoria Square victory celebrations
See the Tigers celebrate their promotion to the Premier League with the fans in Queen Victoria Square
Fans' reactions to Deano's departure
Fans pay tribute to Deano after news of his departure from Hull City
Watch Windass score days before the final
Care of Sky Sports: Peter Beagrie sets up Dean Windass for a volley at North Ferriby
City players visit children in hospital
Hull City players gave children in Hull Royal Infirmary early Christmas presents during their annual visit. Tigers stars Dean Windass, Nick Barmby and Boaz Myhill were among those who handed out gifts
Deano goes back to his roots
Tigers star Windass receives a copy of his family tree
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