His side will be without influential midfielder Tomas Rincon, who is suspended after being sent off in the 2-1 win over Chile in the quarter-finals.
"For me Tomas has been the best player in the Copa even if, when I say it like that, it sounds arrogant," Farias said when his team arrived in Mendoza ahead of their last four clash.
Farias is likely to call on either Giacomo Di Giorgi, Yohandry Orozco or Luis Seijas to replace Rincon.
Venezuela are otherwise set to be unchanged as they bid to reach the final of South America's most prestigious tournament for the first time.
Paraguay look certain to welcome back striker Roque Santa Cruz, who was injured for their victory on penalties over Brazil in the last round.
The Paraguayans are trying to reach their first Copa final since 1979, when they won the last of their two titles.
This will be the sixth Copa America clash between the two sides who met in the group stage of this year's tournament.
Paraguay were leading 3-1 with two minutes to go before Venezuela staged a remarkable comeback to draw 3-3. The Paraguayans had won all the previous encounters.
