Sunderland's players took six days to be talked out of wearing T-shirts showing a black cat mauling a magpie at one of last season's Tyne-Wear derbies, according to a new book.
Jon Smith, who with his brother Phil built the country's first major sporting agency, once looked after more than 400 clients at one time.
In his new book, The Deal: Inside the World of a Super Agent, Smith lifts the lid on one of football's hidden practices.
In an extract in the Guardian, Smith highlights an incident that he claims happened last season when Newcastle were still in the Premier League.