Club: FC Barcelona
The fact that this guy got into Barcelona's first team could be attributed to coincidence or a strange conjunction of the spheres. How he managed to become a regular starter is beyond anyone's explanatory capacity. He achieved much more recognition and attention due to his political ideas (linked with catalan independentism) and verbal clashes with other players (like Salva Ballesta) rather than due to his football abilities. Olegario was always a pretty average defender, lacking both outstanding physical abilities, technique or tactical awareness. He also tended to commit very silly mistakes from time to time, which sometimes made him the perfect target for the media to laugh at. It should be considered a testament to Ronaldinho, Eto'o, Deco, Puyol, Xavi & company the fact that they managed to win a Champions League with this guy watching their backs.
After the disastrous 2007-08 season, Guardiola arrived at Barça's bench and one of his first decisions was to dispose of Oleguer. He was sold to Ajax for an approximated €5M fee, which is widely considered their best sell in history by many Barcelona fans. His new manager, Marco Van Basten, said that he was very happy of having signed Oleguer, since "his qualities fit exactly with what Ajax needs. We are all convinced of that. He has a good age, experience at a high level and is a real defender" (it's been suggested Van Basten was on drugs at the time). Ajax somehow endured him until the end of 2010-11 season, when Oleguer was released of his contract.
Yes, yes, but I featured in a UCL final, and you didn't!