Costa Rica suffered a big blow Saturday when defender Gilberto Martinez was knocked out of the World Cup because of tendinitis in his left leg.

"Gilberto is out because we studied the situation and determined there is no chance he will recover in the next 10 days," Costa Rica coach Alexandre Guimaraes said.

"Gilberto, with the bravery we all know he has, admitted the situation" and agreed to leave the team.

The defender said he was feeling fine before Costa Rica's match with Germany on Friday, a 4-2 loss in Munich. Martinez had to be replaced in the second half of the game.

"This has been one of the most difficult decisions in my career," said Martinez, one of Costa Rica's key team leaders.

Martinez is a talented defender who has made a name for himself playing for Brescia in Serie B, Italy's second division.

Martinez's biggest asset is his versatility: he's able to line up anywhere in defence, although his best position is at the centre of the back line.

Costa Rica next plays Ecuador on June 15 before wrapping up first-round play against Poland on June 20.