They aren't going. This is Mexico's copa america roster:
Goalkeepers
Luis Ernesto Michel Vergara - Guadalajara
Liborio Sánchez - Veracruz
Carlos Felipe Rodríguez - Monarcas
Defenders
Jonny Magallón - Guadalajara
Miguel Ponce - Guadalajara
Darvin Chávez - Atlas
Néstor Vidrio - Atlas
Hiram Mier - Monterrey
Néstor Araujo - Cruz Azul
Paul Aguilar - America
Israel Jiménez - Tigres
Fernando Navarro - Atlante
Midfielders
Jorge Enríquez - Guadalajara
Marco Fabián de la Mora - Guadalajara
Javier Aquino - Cruz Azul
Jorge Hernández - Jaguares
David Cabrera - Pumas
Diego Reyes - América
Néstor Calderón - Toluca
Jonathan Dos Santos - Barcelona B
Edgar Pacheco - Atlas
Forwards
Rafael Márquez Lugo - Monarcas
Javier Cortes - Pumas
Oribe Peralta - Santos
Carlos Vela - Arsenal
Erick Torres - Guadalajara
Mexico is also in the Under-20 world cup this summer and there are some good players on that roster that won't be in copa america either.