The Central American side, after beating China in their opening game, know a win will put them safely into the second round before they take on the mighty Brazilians in their final group C match.

Turkey got close to holding the four-times champions themselves before losing 2-1 but the other result of that game is that they now face the Costa Ricans with two players suspended.

Defender Alpay Ozalan and Hakan Unsal were given one-game bans after their red cards against Brazil -- Hakan Unsal's coming for kicking the ball at Rivaldo, who was later fined by world governing body FIFA for play-acting.

Gunes is playing down the players' absence. "There are plenty of players in our squad who can take their place," he said.

Emre Asik looks set to step in to replace Alpay at left back, while Ergun Penbe will probably come in for Hakan in more of a left wingback role.

Gunes seems likely again to rely on the attacking midfield trio of Yildiray Basturk, Hasan Sas - so impressive against Brazil - and Emre Belozoglu to support Hakan Sukur as a lone striker.

"Even if we had won the Brazil game, we had always looked at Costa Rica as the most critical match," said the coach.

"That is in the past now. We set a target and we haven't given up on it."

The Turks, furious about the decision to award Brazil their match-winning penalty for a foul that took place outside the box, are also unhappy with the choice of Benin's Coffi Codjia for Sunday's game but their protest to FIFA fell on deaf ears.

Gunes describes Costa Rica as a "good and experienced team" and has identified striker Paulo Wanchope as the chief threat. "From an international perspective he is a bit ahead of the others," he said.

Wanchope has been receiving treatment for a long-standing knee injury but looks a certain starter, probably alongside Ronald Gomez, scorer of the first goal against China and provider of Mauricio Wright's second.

Defender Harold Wallace is also likely to play in an unchanged defence having overcome a leg injury.

Cach Alexander Guimaraes could make a change in midfield where Wilmer Lopez could start, relegating the country's all-time leading goalscorer Rolando Fonseca to the bench.

Guimaraes, a player in the team who reached the second round in Costa Rica's only previous finals appearance in 1990, says the current squad, which qualified top of the CONCACAF group, is better.

"Tomorrow we have to write a new page of history," he said

Probable teams:

Costa Rica (5-3-2) - 1-Erick Lonnis; 15-Harold Wallace, 3-Luis Marin, 4-Mauricio Wright, 5-Gilberto Martinez, 22-Carlos astro; 6-Wilmer Lopez, 8-Mauricio Solis, 10-Walter Centeno; 9-Paulo Wanchope, 11-Ronald Gomez

Turkey (4-5-1) - 1-Rustu Recber; 4-Fatih Akyel, 16-Umit Ozat, 2-Emre Asik, 18-Ergun Penbe; 22-Umit Davala, 8-Tugay Kerimoglu, 10-Yildiray Basturk, 21-Emre Belozoglu, 11-Hasan Sas; 9-Hakan Sukur.

Referee: Coffi Codjia (Benin)

Linesmen: Dramane Dante (Mali)

Brighton Mudzamiri (Zimbabwe)