However, there was no last-minute surprise place for Juventus striker Carlos Tevez, who has never been in coach Alejandro Sabella's plans despite his fine form in Serie A.
Demichelis, a veteran of the 2010 finals, had not been called up by Sabella since being dropped after a 1-1 draw at home to Bolivia in a South American qualifier in November 2011.
The 33-year-old, who has 37 caps, put behind him a poor Champions League last-16 performance against Barcelona in February, when he conceded a penalty and was sent off, to secure his place in the centre of the City defence in the title run-in.
Sabella, whose team have often looked unbalanced with a brilliant attack and ordinary rearguard, has noted Demichelis's recent form as he looks to improve his defence for Argentina's tilt at a third World Cup triumph in Brazil.
Another surprise call-up is Catania midfielder Fabian Rinaudo, who won one of his four caps under Sabella in 2011, and is regarded as cover in case regular midfielders Fernando Gago or Augusto Fernandez fail to recover from injury in time to be included in the definitive squad on June 2.
Right back Gabriel Mercado has earned a chance thanks to his performances for River Plate, who can lift the Argentine league title this weekend.
Sabella named Gago of Boca Juniors, Fernandez of Celta Vigo and Real Madrid's Angel Di Maria who all hope to be fit in time for the tournament in Brazil starting on June 12 in which Argentina face Iran, Bosnia and Nigeria in Group F.
Di Maria is fighting to be fit for Real's Champions League final against Atletico Madrid on May 24.
Werder Bremen's Franco Di Santo has been given a chance to stake a claim for a spot in Sabella's star-studded strike force featuring Lionel Messi, Sergio Aguero and Gonzalo Higuain.
Goalkeepers: Sergio Romero (Sampdoria), Mariano Andujar (Catania), Agustin Orion (Boca Juniors)
Defenders: Pablo Zabaleta (Manchester City), Federico Fernandez (Napoli), Ezequiel Garay (Benfica), Marcos Rojo (Sporting Lisbon), Hugo Campagnaro (Inter Milan), Martin Demichelis (Manchester City), Jose Basanta (Monterrey), Nicolas Otamendi (Atletico Mineiro), Lisandro Lopez (Getafe), Gabriel Mercado (River Plate)
Midfielders: Javier Mascherano (Barcelona), Fernando Gago (Boca Juniors), Lucas Biglia (Lazio), Ever Banega (Newell's Old Boys), Ricardo Alvarez (Inter Milan), Augusto Fernandez (Celta Vigo), Jose Sosa (Atletico Madrid), Angel Di Maria (Real Madrid), Maxi Rodriguez (Newell's Old Boys), Fabian Rinaudo (Catania), Enzo Perez (Benfica)
Forwards: Lionel Messi (Barcelona), Gonzalo Higuain (Napoli), Sergio Aguero (Manchester City), Rodrigo Palacio (Inter Milan), Ezequiel Lavezzi (Paris Saint-Germain), Franco Di Santo (Werder Bremen)