Julien Faubert
Many—Faubert incuded—thought it was a joke when Real Madrid attempted to sign the West Ham United man on loan.
His most notable contribution at the Spanish capital was being pictured falling asleep while on the bench.
Keirrison
Ring any bells? Keirrison was the Brazilian wonderkid to arrive at Barcelona from Palmeiras for €14 million in 2009, only to leave five years later having played exactly zero games for the Catalan giants.
He moved back to his homeland on a free transfer. Ouch.