Dipping into the transfer market can be an expensive business in modern football, with clubs sometimes splashing millions on superstars only to be sold on for a fraction of the price.
On the other hand, teams can also snap up the next big thing for peanuts, nurture them into a world-beater and earn a handsome return on their prodigious youngsters.
Using transfer figures sourced from transfermarkt.com, here are five players who have inflicted the worst transfer sale losses on their former club in the history of the game.
You can also check out the biggest ever transfer profits here!
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