Athletic have a six-point lead in fourth spot over Basque neighbours Real Sociedad but have drawn their last two games, away to Valencia and Villarreal, and Iturraspe is keen for the team to return to winning ways against Getafe so they do not squander the opportunity to make it into Europe's elite competition.
He told a press conference: "We might start thinking that we are going to qualify for the Champions League every year and we can't afford start to thinking like that.
"I think that we all know we're going to have to fight in every game. We have to make the two draws more valuable this Saturday at San Mames."
However, Athletic's run of two games without a win pales in comparison to Getafe's dire form - the Madrid side have not won a Primera Division game since November and occupy the final spot of the relegation zone.
But Iturraspe knows Cosmin Contra's side will not make things easy. He warned: "At this stage of the season you cannot predict what any opponent will be like - and even less when it comes to a vital game like this."
New Getafe coach Contra earned a point in his first game in charge since succeeding Luis Garcia, drawing 3-3 with Granada after going ahead three times in the game.
The Romanian was in confident mood when speaking in a press conference before the trip to Bilbao.
He said: "When the fans are on their side they are very dangerous, they press you hard, are aggressive and well organised, but there are aspects to their game that mean we can cause them harm."
Getafe will be without Diego Castro, sidelined for three weeks with a hamstring injury.
Athletic will be without top scorer Aritz Aduriz, who will miss his fifth match this season due to suspension. Gaizka Toquero will stand in for Aduriz - but the 29-year-old has not scored a league goal for 23 months.