Barcelona could be crowned Liga champions should it defeat Athletic and Real Madrid loses the derby to Atletico Madrid later on Saturday evening.
Muniain has urged his teammates to put in the "perfect performance" in order to postpone Barca's title celebrations and help his side reach the target of 40 points to ensure top-flight survival.
“They could be champions if they win, so they will do everything possible. We hope to play well and to delay their title,” Muniain told reporters. “But, we will have to play perfectly if we are to pick up the three points.
“Even though they are going through a slump, the capacity of the players at Barcelona is much greater than at any other team. Therefore, whoever plays for them will make things very difficult.
“We just want to win and make up the points tally to 40 as soon as we can. We will try to steal the ball, make them feel uneasy and play more as it is on our pitch rather than theirs.
“If we can do that, we will have a chance of winning".