Atletico Madrid and Arsenal are both out to save their seasons.
Arsenal are looking to qualify for the Champions league by winning the Europa league, while Atletico are looking to get something from a season that promised so much but has so far delivered little.
The teams play in the second leg of the Europa league semifinals on Thursday.
They drew 1-1 in England last week, when Antoine Griezmann scored late to give Atletico hope despite playing most of the match with 10 men.
Atletico, who have already secured a spot in Champions league and are in second place behind champions Barcelona in the Spanish league with three matches left, had expected to contend for titles both domestically and internationally.
It didn't go as planned, however, and Atletico were eliminated in the group stage of the Champions league — something that hadn't happened in four seasons — and fell to Sevilla in the quarterfinals of the Copa del Rey.
The team did well in the Spanish league by staying ahead of Real Madrid but they never really challenged Barcelona for the title. When they had a chance to move closer, they lost to the Catalan club to see their title hopes all but evaporate.
Arsenal are sixth in the Premier league and need the title to return to the Champions league after a one-year absence.
A failure to make it to the final would keep Arsenal manager Arsene Wenger from winning one last title before bidding his farewell at the end of the season.
Wenger announced two weeks ago he was standing down as Arsenal coach after nearly 22 years at the helm.
Atletico coach Diego Simeone will have to make two changes from the first leg in England.
Sime Vrsaljko is suspended after being sent off about 10 minutes into the match, and Juanfran Torres still hasn't recovered from a hamstring injury sustained in the first half.
left back Filipe luis, out since March because of a broken left leg, has been cleared medically but is not expected to play on Thursday at the Wanda Metropolitano Stadium.