The 33-year-old Demichelis will be hoping just to make the slimmed down 23-man travelling party, although he had support for his cause.
"It was no surprise that he was called for playing in this World Cup, I think he has earned his position," Aguero said.
"He had been criticised, in particular because of the play against Lionel Messi in the (Champions League) match against Barcelona but it is understandable, he wasn't so confident then after starting to play in the English league.
"In the last three or four months, he has been playing very well and adapted and I think that is why he was called up and earned his place in the team."
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