Fourth-placed Villarreal currently boast a nine-point lead over Athletic Bilbao in fifth and, with only five games left after this weekend, Catala feels they would be virtually uncatchable if they return from Andalusian with a three-point haul.
He said: "We know that winning this Sunday that our chances of qualifying for the Champions League will be about 90%.
"We would rule out a strong rival and that's what we've been working towards throughout the week.
"It's going to be similar to the Copa del Rey game," added Catala, whose side lost 6-3 on aggregate to Sevilla in the cup quarter-finals earlier this year despite leading 3-1 at one stage in the first leg.
"They are going to come out fighting and we must learn from that lesson and come out with the same intensity as them.
"For them it's the last chance to get into the Champions League and it's like a final."