With legal matters subsided, the 2005–06 season began. Following midfielder and team captain Patrick Vieira's departure from Arsenal, Gilberto became a senior member of the Arsenal team. Shortly into the season, in September 2005, his desire to see his career out with the club led to Gilberto extending his Arsenal contract to June 2009. A month later this loyalty was repaid when, on 18 October 2005, Gilberto made his first appearance for Arsenal as captain, against Sparta Prague. Although Gilberto had a period of bad form during the winter months of the season, his good defensive performances during the latter stages of the UEFA Champions League (in particular, games against Real Madrid, Juventus and Villarreal) gained him praise. On 17 May 2006 Gilberto played for Arsenal in the UEFA Champions League Final against FC Barcelona, which Arsenal lost 2–1.