The 26-time winners travel west to the third-tier side in the fourth round of the tournament, and the head coach is keen to avoid an upset over the two legs.
Barca have won their last five matches in all competitions and are playing in the Copa del Rey for the first time this season after having a bye in the previous rounds.
However, he has warned those coming in to play to their full potential to ensure they hold a strong advantage going into the second leg in two weeks' time.
"Tomorrow's game against Huesca is a good chance to watch some players who are not having much playing time this season," he said.
"Huesca will be tough opponents and we have to take the game as seriously as we can.
"It will be a unique occasion for Huesca. We are planning not to be the ones who are surprised."
