Five players on Mexico's soccer team, including goalkeeper Guillermo Ochoa and defender Francisco Rodriguez, have tested positive for a banned substance and are out of the CONCACAF Gold Cup.

Decio de Maria, the secretary general of the Mexican soccer federation, said Ochoa and Rodriguez - two starters for Mexico in last year's World Cup - tested positive for clenbuterol. Also testing positive were three role players: defender Edgar Duenas and midfielders Christian Bermudez and Antonio Naelson ''Sinha.''

De Maria said he believes the positive results come from the players eating contaminated beef. Last July, Tour de France champion Alberto Contador also tested positive for the banned anabolic agent and said he consumed the drug in contaminated beef.

But until an investigation is completed, the Mexican players won't be able to play.

''What we presume ... one had to ingest contaminated materials - meat or chicken,'' De Maria said. ''Now comes the tough part, taking the players off the squad and opening an investigation. Meanwhile, it is a disagreeable moment to take this kind of decision, but we have to take responsibility.''

The latest potential doping scandal has the potential to dramatically affect the Gold Cup, the championship of North and Central America and the Caribbean. Mexico, which was to play Cuba on Thursday night, is the defending champion and one of the favorites again this year along with the U.S.

CONCACAF spokesman Ben Spencer said the governing body would meet in a conference call Friday to decide possible sanctions for Mexico and if the team will be able to replace the suspended players. Spencer said Mexico would not lose the three points it received for beating El Salvador 5-0 in the opening match of Group A on Sunday.

''We're still getting information as it comes down,'' Spencer said. ''(Mexico) has chose to separate the players from the team.''

Clenbuterol is used in some countries to treat breathing disorders, but also has been used as a weight-loss drug. De Maria said the players were tested on May 21, but the results weren't revealed until Wednesday.

''Everything points to it being an accident, very unfortunate,'' De Maria said.

Teams were able to bring 23 players to the Gold Cup and dress 18 for each match. Ricardo Osorio already was sent home with an illness, so Mexico was down to 17 eligible players against Cuba at Bank of America Stadium. Jonathan Orozco and Alfredo Torrado are the other goalkeepers on the roster.

Spencer said a decision on whether Mexico would be able to call up replacement players likely would be made before Sunday's final group match against Costa Rica.

Spencer said two Mexican players - Pablo Barrera and Efrain Juarez - passed random drug tests after Sunday's game. The five suspended players were not tested.

The suspensions dampened increased enthusiasm for Mexico's team. Javier Hernandez, who scored 20 goals for Manchester United this season, had a hat trick in Mexico's impressive opening Gold Cup victory.