The 41-year-old saw Barcelona move to within four points of leaders Real at the weekend after the Catalans beat Real Zaragoza 4-1 on Saturday and Madrid were held 0-0 by Valencia on Sunday.
But despite having seen the gap -- which stood at 10 points in February -- reduced to just four points, and with a game between the two sides to come a week on Saturday, Guardiola was still not having any talk of them landing the title.
"I maintain that it is almost impossible for us to win La Liga," said Guardiola, who was speaking ahead of Tuesday's home league game against Getafe.
"One mustn't lose sight of who our rival is. Never in history has any team come back from a 10-point deficit to Real Madrid."
Guardiola, who is out of contract in the summer and has yet to sign a new deal, was at pains to focus the minds of both the public and his players on the immediate task in hand.
The game against Getafe gives Barca the chance to reduce the gap at the top to a single point, piling pressure on Real before they play city rivals Atletico on Wednesday.
"What is important to me is not to talk about Real but to win tomorrow (Tuesday) against Getafe," said Guardiola, whose side are already through to the Spanish Cup final and also play Chelsea in the Champions League semi-finals as they bid to become the first side to retain the trophy.
"My players know already what awaits them at the climax of a really difficult season: to smile less and run more.
"I obviously belong in the camp of those who like to take pleasure out of how we play, but if we wish to win the remaining La Liga games (seven remain), it is vital to run and run, and to be brilliant."
Guardiola said he was especially concerned about the fitness of several of his defenders with French veteran Eric Abidal out for the rest of the season as he awaits a liver transplant and both Dani Alves and Gerard Pique in doubt for the Getafe game with thigh injuries.
"We are stretched to the limit in defence," he said.
"I have only three fully fit defenders. Pique and Alves are extremely doubtful.
"I don't believe they will be able to play against Getafe, but we will see tomorrow."
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