CIDADE DO GALO (Brazil): Argentina striker Gonzalo Higuain, who has had an ankle injury for the past month, is his team's only major worry for their World Cup opener against Bosnia-Herzegovina at the Maracana on Sunday.

In Thursday's training session, Napoli striker Higuain was replaced by Paris Saint-Germain's Ezequiel Lavezzi.

Inter Milan striker Rodrigo Palacio was also on the sidelines on Thursday after suffering an ankle injury in the 3-0 warm-up win over Trinidad last week.

Gonzalo Higuain
Argentina's forward Gonzalo Higuain
 gestures during a training session at the Cidade do Galo training site in Vespasiano, near Belo Horizonte, on Thursday, ahead of the 2014 FIFA World Cup. Pic/AFP 

Meanwhile, defender Ezequiel Garay and midfielder Lucas Biglia claim Argentina have no fear and will go on the attack at the World Cup.

"We're Argentina and we must start winning. We don't fear anyone," said Garay, who said the team would be focusing on supplying Lionel Messi.

"We have to try to give Leo the ball in the best way so afterwards he can destabilise (the opposition) as he's always done."

Biglia said the team was united but warned that their attacking instincts might get the better of them.

"The first defender gets up with the forwards and the first striker gets back with the defenders," said the 28-year-old.

"It makes things complicated because it's a very attacking side."

But Garay, 27, believes the attacking potential in the team is what could make the difference.

"We know that in any moment in a match we will have to all defend, (but) the potential we have up front is impressive and for this reason we have to do the dirty work (defending) so we can give them good ball."

Argentina are in Group F at the World Cup along with Bosnia-Herzegovina, who they play on Monday, Nigeria and Iran.