Argentina call up Demichelis
The Argentine Football Association said on its website that Coloccini had been ruled out after he was injured playing for Newcastle United on Saturday.
Demichelis, who missed this month's defeats by Brazil and Paraguay, has not played since early August when he suffered an ankle injury in Germany.
Argentina are fifth in the South American group and face the prospect of a playoff against the team finishing fourth in the CONCACAF region. South America's top four qualify directly for the finals in South Africa next year.