Greece Coach Fernando Santos assured his men will “attack as much as possible” against fellow surprises Costa Rica.
Their unexpected Round of 16 clash kicks off at 21.00 UK time (20.00 GMT) and is Greece’s first ever World Cup knockout tie.
“I am delighted that we have been able to bring joy to the Greek people,” said Santos in a Press conference.
“We have to pay a lot of attention to this game, as Costa Rica emerged on top in the so-called ‘Group of Death’ ahead of Italy, Uruguay and England.
“Due to this, we cannot allow ourselves to underestimate them.”
Greece were a surprise too, scoring with a last-gasp Georgios Samaras penalty to knock out the Ivory Coast.
They scored only two goals in the entire group phase, but Santos shrugs off claims they are too defensive.
“I have to laugh, really. In football you attack and you defend. We know how to defend, but we are also very good on the counter-attack, as we proved against the Ivory Coast.
“We created many chances and kept attacking to the very end. Against Costa Rica we will attack as much as possible.”