Mascherano stated this in an interview with the UK Guardian, while assessing their Group D opponents.
Argentina are in Group D with Nigeria, Croatia and Iceland.
This will be the third time Mascherano will be facing the Super Eagles at the World Cup. The defender-cum-midfielder was in the Argentina squad that beat the Super Eagles at South Africa 2010 (1-0) and Brazil 2014 (3-2) World Cups.
“Iceland are a new team in the sense that they maybe don’t have a long football tradition but they’re a generation of players that have made history recently, with spectacular success at Euro 16, and qualifying ahead of Croatia.
“Croatia are a first-class side with top players, especially in the midfield, such as Modric, Brozovic, Kovacic, Rakitic … Perisic; a team to watch out, quality squad.
“And Nigeria are quite well known to us, we’ve always met in the last World Cups. They’re tough, not just because of their physical power, but because their disorganisation has the effect of disorganising you as a rival. And that’s when teams like ours suffer the most – in disorder,” he said.