Real conceded a stoppage-time equaliser to draw 1-1 at home to Malaga on Sunday, ending an 11-match winning streak, and Barca's 2-0 win at Sevilla on Saturday left Real on 71 points to Barca's 63 with 11 matches left.
"I can't deny that it's better to be eight points behind than 10 and tomorrow we have to come out and compete again," Guardiola told a news conference ahead of the Spanish, European and world champions' home game against Granada on Tuesday.
"I still think that we won't win the league," added the former Barca and Spain midfielder.
"I am delighted that the fans and the players think we can do it. It's nice to have that hope.
"But it will be very hard to win all 11 games we have left and they [Real] will drop very few points.
"This is the first time we are coming from behind, but the point is that we are coming from a long way back and all the teams have a lot at stake."
Guardiola has had the upper hand over his Real counterpart Jose Mourinho in head-to-head clashes this season but Barca's patchy away form has left them trailing in the league.
The only team to beat Real at their Bernabeu stadium this term, Barca look to have an easier run-in in the league campaign and host their arch-rivals at their Nou Camp arena next month.
Real, who play at struggling Villarreal on Wednesday, still have away games at Osasuna's Reyno de Navarra stadium, where Barca lost 3-2 last month, at city neighbours Atletico Madrid and at Athletic Bilbao.
They also have tough home games remaining against third-placed Valencia and Sevilla.
Barca's trickiest away match looks to be at Levante, who are currently in fourth, and fifth-placed Malaga visit the Nou Camp at the beginning of May.
Both holders Barca and Real are through to the Champions League quarter-finals and could meet in the final.
Barca play Bilbao in May's King's Cup final having disposed of Real in the last eight.
