 He was born and grew up in Mexico City, his family having moved to Mexico in the early 1980s from their native city of Zarautz after his father was relocated for business purposes to that Latin American country.Iturriaga went to elementary school in Mexico, but at the age of 13 his family returned to Europe where he attended St Edmunds College Catholic School near Ware, Hertfordshire, United Kingdom.He showed his natural sporting talents there, quickly learning to play cricket and gaining a place in the Hertfordshire under-14 rugby county team, having played the game for only a few weeks; after high school he finally went back to Spain, where he became a regional junior champion in the racquet sport padel and began to play football with local CD Getxo while planning to study civil engineering.