The sides are due to meet twice in the space of four days, with the second fixture scheduled for Monday, but Bayern Munich striker Pizarro will be absent for both.
It was confirmed last week that the 75-cap forward would be sidelined for "several weeks" after suffering a tear in his right thigh.
"Our intention, every time we play a friendly match, is to improve," he said. "Nobody wants to lose in football.
"It is easier to improve with a victory than with a loss."
Victor Genes' side have won just one of six friendlies since that qualifying process came to an end, and have just two victories from their last 14 international fixtures.
Having occupied a higher position in the FIFA world rankings since 1995, Paraguay have seen Peru overtake them and extend their lead over the last two years.
Peru now sit 22 places higher than Paraguay. Plenty to prove, then, for Genes' men in the forthcoming friendly fixtures.
