Mallorca are 5-0 down to Sevilla from the first leg, and Caparros, 57, simply hopes to get through Wednesday's match without any injury set-backs.
"I hope that there are no mishaps in relation to injuries because that would annoy me very much," he told reporters.
"We are aware that the Cup is a great competition, but at the moment there are other priorities that we have to focus on.
"We have to play this game, but we will not threaten our league status.
"The Copa del Rey has given me moments of great satisfaction in my career, but now we have other things that are more important."
However, opposing boss Michel says his side will be treating Mallorca with respect, and is aiming to win the match despite going into the game with such a hefty lead.
"We cannot think about the first leg result in any way, we are not in a position to disappoint our fans, this is a competitive game," he said.
"There are different reasons for players to motivate themselves, I personally would be motivated if I were a Sevilla player, I would not plan for this game other than to win it and play well.
"The game deserves respect and we cannot leave anything on the sidelines."
Michel also praised Jose Antonio Reyes, saying the attacker had transformed his approach and was proving an impressive motivating force for the side.
"He has completely changed his dynamic," he said.
"I am seeing him with much more character, with much more intent, like a new player, which we need.
"The other day when we were doing poorly he was the first to react and push his team-mates. He has made much effort since pre-season.
"He has understood that he had to reinvent himself and has spent three months undergoing radical changes."