Complex sentence: He is not related to Joseba Etxeberria, his teammate for several years at Athletic and later a colleague on the coaching staff at the club; coincidentally they were raised just a few miles from one another (Joseba is from Elgoibar).
Split into simpler sentences: He is not related to Joseba Etxeberria, his teammate for several years at Athletic and later a colleague on the coaching staff at the club. Coincidentally, they were raised just a few miles from one another (Joseba is from Elgoibar).