Pep Guardiola expects the full effect of Barcelona's 3-2 loss at Osasuna to be felt when Real Madrid meet Levante on Sunday.
Reigning La Liga champions Barca suffered their second defeat of the league season on Saturday, when an experimental line-up went down on a partially frozen pitch at Estadio Reyno de Navarra.
With his team already trailing leaders Real Madrid by seven points in the title race, Barca coach Guardiola expects Jose Mourinho's front-runners to increase the gap with victory over Levante at the Santiago Bernabeu.
"Distancing ourselves from Madrid is painful ... the reality is that we were already at an important distance and I imagine it will increase (tomorrow)," Guardiola said.
"We don't really have many perspectives to work from, we can only play the next game as best we can to do well."
Hosts Osasuna made a flying start to the match, with a brace from Dejan Lekic putting them 2-0 up as early as the 21st minute.
Barca hit back, first through Alexis Sanchez and then with Cristian Tello's goal, but Raul Garcia eventually scored Osasuna's third to secure a famous victory.
"Osasuna were better in the first half," Guardiola said.
"We played a great second half, anything could have happened."
"Osasuna started off and adapted to the pitch conditions better than we did."
"If we were playing well in the second half on this pitch we could have done the same in the first."
The defeat looks set to cost Barca more than ground in the title race.
Javier Mascherano was reportedly shown a second yellow card by referee Jose Romero after the match, meaning the Argentina midfield will incur at least a one-match domestic suspension.
Guardiola was reportedly also censured in the referee's match report for protesting Mascherano's punishment.