Barca head into this match on the back of a humiliating 4-0 defeat to Atletico Madrid in their Copa del Rey semi-final first leg encounter at the Riyadh Air Metropolitano last Thursday.
However, Barca have an opportunity to reclaim top spot on the LaLiga table from arch-rivals Real Madrid when they face 15th placed Girona, who are winless in their last three league matches.
"Girona are a well-organised team, brave, who play out from the back well. We will have to be very intense," said Flick to the press ahead of the match.
"We lost on Thursday [vs Atletico] and it was a lesson, but life goes on. You have to accept the defeat and have confidence. We have a lot of quality to get over it.
"You can lose, but how you react is important. And I want to see the reaction tomorrow."
The German mentor also confirmed that England international forward Marcus Rashford will not be available for the Catalan derby at Girona, but Brazilian star and captain Raphinha is fit to play after missing the last three matches due to a hamstring strain.
Hansi Flick has admitted there was a "clear" foul in the build-up to Girona's late winner, but the Barcelona manager refused to hide behind officiating complaints after his side slipped to a damaging 2-1 defeat at Montilivi.
A disagreement between Diego Simeone and Jan Oblak summed up a forgettable night for Atletico Madrid, following their damaging 3-0 defeat to Rayo Vallecano.
Barcelona could be without Marcus Rashford for their upcoming derby against Girona after the forward sustained a knee injury in last weekend's La Liga win over Mallorca.
Frenkie de Jong expressed frustration after Barcelona suffered a 4-0 defeat to Atletico Madrid in the first leg of their Copa del Rey semi-final, a match marred by controversial officiating.
