The All Blacks are favourites to progress to the semi-finals from the last-eight clash at Eden Park this Sunday (8.30am kick off) and Agulla says the Pumas will have to focus for the full 80 minutes to provide a shock.
“It's a big challenge for us playing against the best team in the world,” said 26-year-old Agulla.
"It's going to be a massive game and a dream to play in New Zealand at the World Cup against New Zealand.
"You cannot give them 10 minutes, otherwise they can score five tries over you.
"We have to be smart and play with our heart and lots of passion.
"We have to be 100 per cent focused. We have to trust in ourselves and each other."
Belief the All Blacks can end a 24-year wait for World Cup glory has wavered since the tournament-ending groin injury suffered by inspirational fly-half Dan Carter.
But Agulla, who made 22 appearances for Tigers last season, says the hosts have the strength in depth to cope.
He said: "Dan (Carter) is the best fly-half in the world, but New Zealand is always going to find players with plenty of talent."