Former Pumas hooker Ledesma was chosen for four consecutive World Cup tournaments between 1999 and 2011 and loose forward Juan Manuel Leguizamón equals that record after making the squad for Japan.
Argentina have played 37 World Cup matches, winning 19 and losing 18, with the best showing a third-place finish at the 2007 tournament hosted by France.
Their World Cup record against their pool opponents in Japan is mixed. They have won two of three clashes with France, beaten Tonga the only time they played and lost both meetings with England. They have never faced their final pool opponent, the United States, at the tournament.