Upon his return to Ajax, Reiziger established himself as a renowned defensive element, helping the side to, among other conquests, the 1994–95 edition of the UEFA Champions League. In 1996 he signed for A.C. Milan, but after a season marred by injury, he departed for FC Barcelona where he spent the following seven years, arriving at the same time as compatriot and former Ajax boss Louis van Gaal; though not an undisputed starter, he nonetheless featured heavily for the Catalans, making more than 200 overall appearances and helping to back-to-back La Liga titles.