He said the decision was part of the tactics he had devised for Messi to have a brilliant tournament and inspire Argentina to clinch the South American title they last won in 1993.
Less than a month ago, Tevez appeared out of the running for a place in Argentina's squad but he and Batista cleared the air over issues that had kept the striker out of the reckoning and he has impressed the coach in training.
"Carlos will play because he can link much more with Lionel and the idea is not to have players of such speed as we would have if [Angel] Di Maria and [Ezequiel] Lavezzi played [either side of Messi]... with Carlos we have more play," he told reporters on Thursday.
Batista, who has dropped Di Maria to the bench to make way for Tevez, denied he had bowed to popular demand and media pressure to include the Manchester City captain.
"I don't go by popular clamour. If I say Tevez must play it's because that's best for the national team. He has earned his place on his own," Batista said.
Batista said he had alternative tactics if Messi were suffocated by Bolivian marking.
"We discussed Messi getting man-to-man marking and we have a plan B, someone [else] who will take control of the team and the ball," he said.
"Lionel must enjoy what he's doing, he's a great player, the world's best, and we'll take maximum advantage of that. We built a team for him and let's hope it's his Copa America."
Argentina team (4-3-3):
Sergio Romero; Javier Zanetti, Nicolas Burdisso, Gabriel Milito, Marcos Rojo; Ever Banega, Javier Mascherano, Esteban Cambiasso; Ezequiel Lavezzi, Lionel Messi, Carlos Tevez.
