For Barcelona, the Copa del Rey title would reassert its dominance. For Sevilla, it would help save its season.
While Barcelona will be trying to win the title for a fourth straight time on Saturday, Sevilla will be hoping to salvage a season that started with high expectations but could end without any trophies or a place in European competition next season.
Because of its poor campaign in the Spanish league, not even a place in the Europa League is guaranteed unless it wins the Copa del Rey.
"We can't think about anything other than the final," Sevilla midfielder Pablo Sarabia said. "We have to stay focused to try to win this title any way we can. This is the most important match of the year for us."
Sevilla got off to a good start this season, staying near the top in the Spanish league and looking like a possible title contender along with Barcelona and Real Madrid.
It also began thriving in the Champions League, comfortably making it through the group stage and eventually eliminating Manchester United in the last 16. In the Copa del Rey, it got past favorite Atletico Madrid in the quarterfinals.
But Sevilla wasn't able to keep playing at a high level throughout the season.
The team underwent a coaching change during the winter break, with Vincenzo Montella replacing Eduardo Berizzo. Under the Italian coach, Sevilla was eliminated by Bayern Munich in the Champions League quarterfinals and dropped to seventh place in the Spanish league, outside the qualification zone for the Europa League.
With five games left, it is three points behind sixth-place Villarreal and 17 points behind fourth-place Valencia, the last team guaranteeing a Champions League berth next season.
"We have a great opportunity to give Sevilla another title," Sarabia said. "We have to look at the good things we did this season. It's true that we haven't played consistently in the league, but in the Champions League we made history (by reaching the quarterfinals) and in the Copa we remain with chances of winning the title."
Sevilla will be trying to win its sixth Copa de Rey title, and the first since 2010. Two seasons ago, the team lost to Barcelona in the final.
The Catalan club has been dominant in the tournament recently, winning the title in four of the last six seasons. It will be looking to win a record-extending 30th trophy in its fifth consecutive final.
No team has won four titles in a row since Athletic Bilbao from 1930-33. Before that, only Madrid won four straight, from 1905-08.
"We are not afraid," Sarabia said. "We will use our weapons and try to make them feel uncomfortable throughout the match."
Sevilla came close to beating Barcelona at home in a league match month, opening a 2-0 lead before Luis Suarez and Lionel Messi scored in the final minutes. Barcelona won 2-1 when the teams met at Camp Nou.
Barcelona is about to clinch the Spanish league title, but it lost the chance of winning the treble when it was eliminated by Roma in the Champions League quarterfinals. With the Copa del Rey final in mind, Barcelona coach Ernesto Valverde rested Lionel Messi and most of the team's regular starters in the 2-2 draw at Celta Vigo on Tuesday.
"We had to take some risks with the changes considering that we have a final to play," Valverde said.
The final will take place at Atletico Madrid's Wanda Metropolitano Stadium in the Spanish capital, and there is concern about the crowd's behavior considering the ongoing political turmoil involving Catalonia and the Spanish government over the region's bid for independence.
The club said it will display a huge banner with the yellow-and-red colors of the official Catalan regional flag before the match, along with the words "Barca, Barca, Barca."
Jeers are widely expected by part of the Catalan fans during Spain's national anthem even though Valverde said the club's position is to respect the hymn. Many Barcelona fans wanted the team to play with a red-and-yellow uniform representing the regional flag.
"I'm not going to say anything," Valverde said. "I just want the players to recognize each other."