Pedro Sarabia is wary of Barcelona's attacking threat as Libertad prepare to travel to Ecuador for Thursday's first-leg clash.
Barcelona and Libertad will go head-to-head at the Estadio Monumental Isidro Romero Carbo in the second round of the Copa Sudamericana.
Libertad - second in the Paraguayan Division Profesional - advanced from the first round thanks to a three-goal return leg as they overcame Nacional Potosi 3-1 on aggregate.
Ecuadorian Primera A leaders Barcelona had it a little easier against Alianza Lima, keeping successive clean sheets to triumph 3-0 over two legs.
Speaking ahead of Thursday's opening leg in Guayaquil, Libertad coach Sarabia said he is prepared for an attacking onslaught from the hosts, who are unbeaten in 12 games on home soil.
"We have already seen videos and we know that Barcelona is a team that goes out to get a game, an offensive team," Sarabia told Radio Huancavilca.
"Barcelona is a fast team together well armed, is a team that plays well and will block attacks and defends in blocks."
Sarabia, whose team have lost their past three games on the road, will be reunited with Barcelona coach Ruben Israel.
Israel was in charge of Libertad during Sarabia's playing days.
"Ruben Israel is like my second father. I said someday we would face at any moment," said Sarabia.
Huachipato are also in action on Thursday, playing host to Universidad Catolica in Chile.
Mario Salas' men - third in the Primera Division - had no trouble in front of goal as they beat San Jose 6-4 on aggregate.
And Huachipato will be hoping for a good start against Catolica as they attempt to reach the third round.
Catolica needed penalties to get past Deportivo Anzoategui after scores were locked at 2-2 on aggregate.
On Wednesday, Colombian giants Atletico Nacional welcome Paraguay's General Diaz to the Estadio Atanasio Girardot.
Winners of 14 domestic league titles, Nacional were too strong for Deportivo La Guaira in the first round, winning 2-1.
And the Primera A side are in good form, having gone four games unbeaten after Sunday's 2-2 draw at home to Boyaca Chico.
As for General Diaz - fourth in the Division Profesional - they are on a 20-game winless streak in all competitions away from home, despite prevailing over two legs against Cobresal.