Two Mexican League players tested positive for the steroid Clenbuterol during the opening weekend of action, Mexican Soccer Federation president Decio de Maria told ESPN's Graciela Resendiz on Tuesday.
De Maria said the federation would not be releasing the names of the players until the investigation was complete. He said disciplinary committee president Eugenio Rivas would be in charge of the sanctions for the players in question.
Although the players were not named, neither America, Tigres, Chivas nor Santos played in the first weekend of action, nor did the national team players who were seeing action in the 2013 Gold Cup.
In the most recent doping case in Mexico in 2011, Antonio Naelson, Sinha, Francisco Rodriguez, Christian Bermudez, Guillermo Ochoa and Edgar Duenas all tested positive for Clenbuterol.