Jereb qualified for the Slovenian squad, as a lone male judoka, in the men's lightweight class (73 kg) at the 2004 Summer Olympics in Athens, by placing seventh and receiving a berth from the European Championships in Bucharest, Romania. He lost his opening match to Iranian judoka Hamed Malekmohammadi, who successfully scored an ippon and an uchi mata gaeshi (inner thigh counter), at three minutes and twenty-eight seconds.