Barca host their bitter rivals at the Nou Camp in a match that could prove decisive in the La Liga title race with Real four points clear at the top with five games left.
Guardiola, who ran Barca's midfield in the 1990s much in the same way Xavi does now, has an impressive record in 'Clasicos' as a coach, leading the current Spanish and European champions to nine wins, four draws and only a single defeat in all competitions since taking charge in 2008.
However, he said he had not enjoyed the last few times the two sides had met, when players from both sides clashed, Real coach Jose Mourinho jabbed a finger into the eye of Guardiola's assistant Tito Vilanova during a mass brawl and there were allegations of refereeing bias, diving and racism.
"It's nicer to play a 'Clasico' than experience it from the bench as you have more influence," Guardiola told a news conference.
"I don't have very good memories of the last few Barca-Madrid games, in victory or defeat, and I did not enjoy them," added the 41-year-old.
"A lot of things happened that I did not understand but the past is the past and tomorrow a lot of people will be watching us."
Hundreds of millions will tune in for Saturday's game, a record sixth meeting for the world's two richest clubs this season which has added significance as the pair could meet again in next month's Champions League final.
It will be their 219th official match and they have won 86 each, with 46 draws. If Barca win they will lead the head-to-head series for the first time in 80 years.
This term they beat Real in the season-opening Spanish Super Cup, knocked them out of the King's Cup and came from a goal down to win 3-1 at the Bernabeu in December.
That victory could be decisive as if they finish level on points the title will go to the team with the better head-to-head record.
"If they win or draw (tomorrow) the league is theirs," said Guardiola, who is chasing a club record-equalling fourth straight La Liga title.
"Our only remaining option is to win and if we don't we will already have a new champion," he added. "We will congratulate them and start preparing for next year."
Guardiola should have all his players available except long-term injury casualties David Villa and Ibrahim Afellay and Eric Abidal, who is recovering from a liver transplant.
The only doubt is forward Alexis Sanchez, who suffered a bruised leg in Wednesday's 1-0 Champions League semi-final first leg defeat at Chelsea.
"He trained on his own today," Guardiola said. "He has less pain so we'll see tomorrow."
Barca are unbeaten in the last seven La Liga 'Clasicos', winning six and drawing one and are on an 11-match winning streak in the league.
They have not lost in their last 34 home games in La Liga and are undefeated in their last 54 at the Nou Camp in all competitions.