Last season the Catalan giants were upset twice by their upstart minnow neighbours, who thumped Xavi Hernandez's side 4-2 home and away in the top flight.
Girona, in their fourth ever season in La Liga, ultimately finished third, behind second-place Barca, but for much of the season the Blaugrana could only watch as the tiny club battled Real Madrid for top spot.
Although Girona's title bid eventually collapsed, their second triumph over Barca secured them Champions League football and delivered Madrid's record-extending 36th league crown.
A lot has changed since then, with Flick's arrival in place of Xavi seeming to revitalise Barcelona's squad.
Led by teenage star Lamine Yamal, new arrival Dani Olmo and veteran striker Robert Lewandowski they have won their opening four matches and are the only team in La Liga with a 100 percent record.
Girona, on the other hand, have lost star names including Artem Dovbyk and Savinho and coach Michel Sanchez is still fitting together his replacement puzzle pieces.
After a 3-0 thumping by Atletico, Girona responded with 4-0 and 2-0 wins over Osasuna and Sevilla respectively, indicating they are on the right track once more.
"It was a difficult market because we had an excellent season, we knew it could be a long window," said Girona sporting director Quique Carcel earlier this week.
"We did what we had planned, which was to think about the players who might leave -- we had planned for some of them.
"We looked for profiles which, with our style of play, the coach needed... we are happy with the squad we have."
Girona brought in Arnaut Danjuma, Bryan Gil, Abel Ruiz and Donny van der Beek, among other arrivals, as well as Oriol Romeu from Barcelona on loan.
The midfielder cannot face Barca because of a clause in the deal, while Yangel Herrera is also a doubt.
Flick has a long injury list to manage but is expecting to have playmaker Olmo available despite suffering a blow against Serbia while playing for Euro 2024 winners Spain.
Morale is high at the club because of their fine start, including a 7-0 demolition of Valladolid before the international break, and Gavi's partial return to training on Thursday after a long injury lay-off provided further good news.
"We work much harder than before," Barca midfielder Pedri told Mundo Deportivo.
"The team doesn't dip after the 70th or 80th minute, it maintains the same fitness levels."
Many expected champions Real Madrid to defend their crown with ease after signing Kylian Mbappe this summer but if Barcelona can avenge last year's double defeat at Montilivi, it would be a statement victory.
Los Blancos travel to San Sebastian on Saturday to face Real Sociedad, having drawn two of their first two matches, yet to fire on all cylinders.
Player to watch: Julian Alvarez
Atletico's new signing from Manchester City Julian Alvarez has yet to find the net but with bottom of the table Valencia travelling to the Metropolitano Stadium on Sunday, the Argentine will be aiming to open his Rojiblancos account. The visitors have lost three of their opening four La Liga matches.
Key stats
1 - Barcelona are the only team left in La Liga with a 100 percent record thus far
3 - Atletico Madrid host Valencia having kept three consecutive clean sheets
25 - Real Madrid's Kylian Mbappe has taken the most shots in the league
Fixtures (all times GMT)
Friday
Real Betis v Leganes (1900)
Saturday
Mallorca v Villarreal (1200), Espanyol v Alaves (1415), Sevilla v Getafe (1630), Real Sociedad v Real Madrid (1900)
Sunday
Celta Vigo v Real Valladolid (1200), Girona v Barcelona (1415), Las Palmas v Athletic Bilbao (1630), Atletico Madrid v Valencia (1900)
Monday
Rayo Vallecano v Osasuna (1900)
