Depor were humbled 5-1 last Sunday at the Bernabeu and despite taking a shock lead through Riki, Cristiano Ronaldo put them to the sword with a hat-trick.
Oltra made no attempt to hide his disappointment with their performance and although they stretched their winless streak in the La Liga to five matches, he ruled out making wholesale changes for the clash at Rayo Vallecano.
"I'm not unhappy with the team, except the last game, but that's why we should not sweeping changes. We should give our players confidence and I believe in what we do," Oltra said in AS.
"There will be no revolution but there are always emergencies.
"When you take longer without winning, you have more need. The group is very quiet."
Depor, promoted from the Segunda Division last season, have not won since their opening day 2-0 success over Osasuna, while Rayo Vallecano will be hoping to end a three-game losing streak.
Rayo chairman Raul Martin Presa insists the club have learned their lessons from their last home game against Real Madrid, which was rescheduled 24 hours after the original clash was set to take place.
Presa told Spanish media at the time that he suspected an act of sabotage had been responsible for an electrical fault that caused an initial postponement but he is confident there will be no repeat .
"We have tightened security and tried to put all the steps within our reach," he told his club's official website.