Mainz midfielder Elkin Soto, Al Shabab's Macnelly Torres and America defender Aquivaldo Mosquera have been axed.
Colombia continue to sweat on the fitness of star striker Radamel Falcao as he recovers from a serious knee injury, with Pekerman facing more selection decisions before the final party must be announced on June 2.
Colombian Football Federation president Luis Bedoya told reporters: "There are 26 players in Bogota.
"They will fly to Argentina, where they will meet up with Radamel Falcao and there four (more) will be taken out of the group."
Colombia begin their World Cup campaign against Greece in Group C on June 14 before facing Ivory Coast and Japan.
Squad in full:
Goalkeepers: Faryd Mondragon (Deportivo Cali), David Ospina (Nice), Camilo Vargas (Independiente Santa Fe)
Defenders: Santiago Arias (PSV), Pablo Armero (Napoli), Eder Alvarez Balanta (River Plate), Luis Perea (Cruz Azul), Carlos Valdes (San Lorenzo), Mario Yepes (Atalanta), Cristian Zapata (Milan), Camilo Zuniga (Napoli)
Midfielders: Abel Aguilar (Toulouse), Juan Cuadrado (Fiorentina), Fredy Guarin (Inter), Victor Ibarbo (Cagliari), Alex Mejia (Atletico Nacional), Juan Fernando Quintero (Porto), Aldo Ramirez (Morelia), James Rodriguez (Monaco), Carlos Sanchez Moreno (Elche), Edwin Valencia (Fluminense)
Forwards: Carlos Bacca (Sevilla), Radamel Falcao (Monaco), Teofilo Gutierrez (River Plate), Jackson Martinez (Porto), Luis Muriel (Udinese), Adrian Ramos (Hertha Berlin)
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