An improved defensive discipline has been the key to Costa Rica's success in Brazil, according to assistant coach Paulo Wanchope.
Costa Rica secured a round of 16 berth at the FIFA World Cup with a shock 1-0 win over Italy in Recife on Friday, having already stunned Uruguay 3-1 in Group D.
While Italy had over 60 per cent possession at the Itaipava Arena Pernambuco, they only managed four shots on target, while Costa Rica were always threatening on the counter-attack, producing five efforts that tested Italian goalkeeper Gianluigi Buffon.
Captain Bryan Ruiz scored the winner for Costa Rica just before half-time and Wanchope said with the talent in the forward third of their skipper, plus Joel Campbell, Christian Bolanos and Marco Urena, the CONCACAF nation can always trouble opponents.
They simply must ensure they do not concede too many goals at the other end.
'''I mean we work hard, we want to impress the world, we want to be a better team," Wanchope said on Sunday.
"We have been improving for the last year and a half. We knew that we need to work a lot on the defensive side, we need to be more disciplined because we knew that we had great players that mean we can score against anyone but we had been working very hard on the defensive side.''
Costa Rica had started the World Cup with a record of one win, three losses and a draw in matches this year, conceding 10 goals in five games but have been defensively frugal in Brazil.
Playing a 5-3-2 formation, Colombian coach Jorge Luis Pinto has ensured Costa Rica have denied the likes of Edinson Cavani of Uruguay and Italy's Mario Balotelli in their opening two matches and the Central Americans have now qualified for the round of 16 for just the second time in their history.
Wanchope said he accepted that many did not expect Costa Rica to do so well in a group that included 2006 champions Italy, 2010 semi-finalists Uruguay and the birthplace of football - England.
"I mean we are realistic. We knew that the world would expect either Uruguay or Italy or England to go through, that's normal because of the history and all the facilities the other teams have," the former striker said.
"When you have talented players and when you work hard you have a chance."
Meanwhile, Wanchope appeared unfazed by FIFA's demand that seven Costa Rican players - five more than the usual two - undergo doping control following their win over Italy.
The FIFA directive was slammed by the Costa Rican Football Federation and Pinto on Saturday but Wanchope claimed he was not surprised.
''It's strange but we are nice and cool. It's something that FIFA always do," he said.
"Not the right things but they do it. Everytime they change the rules or something but they have the right to do it.
"If they need 11 or the 23 to blood test, it's no problem."