With Barca having already cruised to a comprehensive 4-0 triumph against Osasuna in their last-16 first leg match, the second encounter was always going to be a dead rubber affair and although a Dejan Lekic strike put Osasuna 1-0 up at the break, the Nou Camp outfit equalized through Alexis Sanchez before youngster Sergi Roberto put the game beyond doubt to ensure Barca progressed with a 6-1 aggregate win.
Speaking to the club's official website during the post match press conference, Guardiola labeled Jose Mourinho's charges as "a great rival", remarking that their quarter-final ties will be "great and exciting for the spectators."
"Both us and them are teams that, no matter what competition we are playing in, we try to win," Guardiola explained.
"It seems as though, whatever the result is, that the world will end. If we go on or not the games in the Liga are assured."
"When you play against rivals like Real Madrid the possibilities of winning or losing are always there."
Guardiola insisted that Madrid's five point lead over Barca in the La Liga standings will not have any influence whatsoever during their Cup clashes.
"If we were five points ahead we'd go into this tie to win it just as we will go to win it being five points behind, just like Real Madrid would. We are two team, two institutions that try to win everything that we compete in," he said.
Assessing the display of his largely-second string side against Osasuna, Guardiola lavished praise on goalscorer Roberto.
"He can play anywhere, he's too good, his start is great," he purred.
"We needed someone that looked for spaces, that made us a bit deeper. His movements are good. I congratulate him."
Guardiola also complimented on the performance of precocious fullback Martín Montoya.
"Barça has a good right back for the future," Guardiola added.
The former Barca skipper also declared that his side will not be making any forays in the ongoing winter transfer window.
"With the injuries we've had this year, we'll need the reserves a lot. They need to get ready. We have a reserve side, and I believe in many of them. The fewer we are the more difficult it will be to move forward," Guardiola concluded.