"This will result will serve to keep our feet on the ground," the Brazilian was quoted as saying in sports daily El Mundo Deportivo on Friday following his side's 4-2 defeat at Real Zaragoza in the King's Cup.
"They (Zaragoza) took full advantage of the chances they had and these things happen in football, but we are sad because we are used to winning every game and we couldn't keep it going."
Zaragoza stunned the Catalans with three perfectly executed goals in the space of five minutes to take a 3-0 lead in the King's Cup quarter-final first leg before the half-hour was up.
Barca clawed their way back to make it 3-2 just after the hour, but a late penalty from Argentine striker Diego Milito gave Zaragoza a handy two-goal advantage ahead of next week's return leg.
The defeat, which came in similar fashion to their 4-2 loss to Chelsea in last season's Champions League, brought an abrupt end to Barca's 18-match winning streak in all competitions.
Coach Frank Rijkaard, who had decided to rest inspirational defender Carles Puyol and first-choice goal keeper Victor Valdes for Wednesday's match, said he was confident his team could rectify its defensive problems.
"Conceding three goals in such a short time has to be avoided and we need to reflect on this performance," he told a post-match news conference.
"It would be worrying if we didn't know what we had to do to correct this, but that is not the case."
If Barca manage to oust Zaragoza they will face arch-rivals Real Madrid in the semi-finals.
