They took on the Mariners Youth in a training game at Parramatta Stadium, as part of that preparation.
"It's a great experience and something the boys will remember for a long, long time," said Mariners Midfielder Brendan Griffin.
"We're here for them and we can't understand what they're saying but they show direction and stuff. They put out cones and markers in areas we're not allowed to go (tactically), so we stuck to that and played some good football."
While the biggest name in the Paraguayan squad, Manchester City maestro Roque Santa Cruz was absent, Griffin still admitted he and his teammates were well aware of the quality of company they were dealing with.
"As you saw they are quality, but we tried our best and I think we did OK. They seem to be able to keep the ball for hours!" laughed Griffin.
"We seemed to have the ball for a second and then there were three people around us, they're so quick in transition, World class," Griffin said.
The young Mariners may have needed a confidence boost too after a disappointing result against the AIS, and Griffin says confidence was one thing acquired in spades during a physical hit-out.
"You come from playing 16, 17 year olds to people who have just played at the World Cup, and I think we did alright out there.
"I hope all the boys do (draw confidence), and hopefully that will show on Saturday," said Griffin.
Tony Walmsley's young charges face off against bottom side Melbourne Victory at Budgewoi this Saturday morning, and Griffin insists the side will take memories of what is likely to be a once in a lifetime week for many of the squad members into the clash.
"It's a bit different on matchday but we're going to take what we learn from here, take it into training and then hopefully take it into the game on Saturday," Griffin said.