
The Brazilian posted a copy of the document to his Instagram account, which shows him authorising an agent to act on his behalf this month.
The 29-year-old, who has been linked with a move away from Stamford Bridge this summer, insisted he had never signed such a document.
In a post on Instagram, Willian said: “In the recent days I have been informed that a “letter of authorization for player agent FIFA”, allegedly signed in my name has been circulated through the football market.
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