1-Dmytro Chygrynskiy-
Chygrynskiy moved to Barcelona from Shakhtar Donetsk for €25 million in 2009. He was on the sidelines during most of his only season at the Camp Nou. And in the 12 appearances he made for the club, he fared poorly. He was offloaded to former club Shakhtar for €15 million in 2010. As a result, Barcelona was left €10 million poorer.
He can be considered as a complete failure. Not only did he not play well for Barca, his transfer back to his former club made the club incur a loss.