By Arturo Silva

CHICAGO, July 9 (Reuters) - Cuba are down to a squad of 16 for their opening CONCACAF Gold Cup soccer match against favourites Mexico on Thursday after one of their players deserted.

Assistant coach Walter Benitez said a player, whom he did not name, had abandoned the Cubans' base in Chicago and the team did not know where he was, adding to visa delays suffered by six other players and coach Raul Gonzalez.

"We're missing six members of the squad and the coach who, because of visa issues, have not been able to arrive (yet) and now we have only 16 players because one has gone absent (and) we don't know where he is," Benitez told reporters after Wednesday's training.

Cuba face Mexico in a Group C match at Soldier Field later on Thursday (0130 GMT Friday).

"Nevertheless we're working with a lot of dignity and we're going to give our best against Mexico," Benitez said, adding Cuba had problems picking their best team from the 16 players present.

"It's been very difficult. The lad who went away was a first-choice player but we'll manage. We came to play a tournament and we're going to play it, the rest is personal decisions," he said.

Gonzalez and six members of Cuba's under-23 team were scheduled to join the rest of the squad on Thursday morning after taking part in an Olympic qualifying tournament.

Communist Cuba has a long history of sporting defections and six players abandoned their soccer team at the 2013 Gold Cup in the United States. (Additional reporting by Carlos Calvo in Mexico City; Writing by Rex Gowar; Editing by Ken Ferris)