Javier began his professional career in Argentina, first with Talleres, and then Banfield.
In 1995 Javier made the move to Itay, where he joined Serie A club Inter Milan.
Javier remained at Inter Milan for 19 seasons, making 858 appearances across all competitions (club record for most appearances and longest tenure.)
During his time at Inter Milan he won 16 trophies, 15 of which came under his captaincy.
Javier led the club to four Coppa Italia titles, four Supercoppa Italiana titles, Five Serie A (Scudetti) titles, the 1998 UEFA Cup, 2010 Club World Cup and the 2009–10 Champions League trophy.
Javier made 145 appearances for Argentina between 1994-2011, when he reached the final of the Copa América in 2004 and 2007, and the Confederations Cup in 1995 and 2005.
Inter Milan retired his iconic number 4 shirt after his retirement in 2014.