Sao Paulo - Brazil and Argentina will try to kick-start their World Cup qualifying campaigns on Tuesday after opening losses but withdrawals have hit two teams already suffering without their stand-out strikers.
Argentina face a tough task in Paraguay with Carlos Tevez likely to start up front in place of the injured Sergio Aguero.
Aguero limped off midway through the first half of Argentina's 2-0 loss at home to Ecuador last week, his injury a blow to a side already without Lionel Messi, who is out for two months with a knee injury.
Adding to their woes, Lazio midfielder Lucas Biglia withdrew with a thigh strain and Ezequiel Garay has left the squad to be with his expectant wife.
The rambunctious Tevez will be charged with getting the goals and upping the tempo and the Boca Juniors striker admitted Argentina lacked character against Ecuador.
Tevez said they must react immediately if they do not want to be left behind in what is already being seen as the region's toughest qualifying competition ever.
Four of the 10 teams go through automatically and the fifth face a playoff but Argentina and Brazil have never both started their campaigns with defeats.
"The team didn't step up at any time (against Ecuador) and that is worrying," Tevez said.
"In these situations we need to show some attitude. We didn't start well but we'll have a chance to make up for it on Tuesday."
Paraguay beat Venezuela 1-0 away to get their campaign off to the perfect start and a full house is expected for a match given extra spice by the meeting of two Argentine coaches.
Ramon Diaz leads Paraguay, while Gerardo Martino is going back to a nation he led at the 2010 World Cup.
Brazil have a seemingly easier task at home to Venezuela, the only South American nation never to qualify for the World Cup finals.
Brazil lost their opener 2-0 away to Chile and they will again be without their talismanic Barcelona forward Neymar.
He will serve the last a four-match suspension and Brazil will also be without David Luiz, who picked up a knee injury against the Copa America champions.
Paris St Germain's Marquinhos will replace Luiz at the centre of defence and his club team mate Lucas could also play a role up front. Santos midfielder Lucas Lima looks set to play just his third game in a Brazil shirt.
Elsewhere, Peru will look to get some points on the board against Chile after losing their opener 2-0 in Colombia, while Ecuador take on Bolivia at home.
Uruguay host Colombia in the only match between two unbeaten sides after they won 2-0 in La Paz for their first victory against Bolivia at high altitude.