The English side face a daunting task at home against the record 15-times European champions, who have knocked them out of the past two editions of the Champions League.
"After 10 years you have to convince some of my players about their belief? They know me quite well. Every single game we try. This will be no exception. They have to," Guardiola told reporters.
"I am pretty sure they will try it. Of course most of them are new to experiencing such situations. We are not the same group we had for many years but, at the same time, it is an incredible experience and an incredible opportunity to try it...
"It's a football game; many things can happen. You have to focus and first try to win the game then after that we will see what happens during the game. I don't have a specific plan. Just try it."
Training cancelled
Guardiola opted to cancel training on Monday and give his players the day off before the game, with the squad to train on Tuesday instead.
Asked if resting his players would help them mentally, the Spanish manager said: "It's related. The way you play, if you play good mentally you will be strong.
"I am not much concerned about the chances we are going to create, I am pretty sure that we are able to do it. At home we are always able to do it. It is more about how well we are going to defend.
"The task is massive, to score more than three goals against Real Madrid, it is not easy. The result in the first leg is not the perfect one but at the same time we are here, it is a football game, everything can happen."
Fight to the end
City captain Bernardo Silva, who was tasked with media duties on Monday, joked he was the only player who did not get a day off.
"We've done it in the past, plenty of times. When we lost games, when we've won games, when the manager felt it was best for the team," the Portuguese international added.
"With all the trips we've had, this week, I think he felt it best for us to sleep better and come back tomorrow stronger and ready for the game...
"This sport has taught us that a lot of things can happen. Even though the result in Madrid was really bad, we will fight until the end."