Real Madrid won the UEFA Champions League, while Atalanta won the UEFA Europa League.
The two sides are meeting for the first time at this stage of European football.
Real Madrid, AC Milan and FC Barcelona are the most successful teams, with five titles each.
Here are the most winners list
Real Madrid (5 Titles)
FC Barcelona (5 Titles)
AC Milan (5 Titles)
Liverpool FC (4 Titles)
Atletico Madrid (3 Titles)
Chelsea FC (2 Titles)
Bayern Munich (2 Titles)
Ajax (2 Titles)
Anderlecht (2 Titles)
Valencia (2 Titles)
Juventus (2 Titles)
Sevilla CF, FC Porto, Manchester United, Dynamo Kyiv, Nottingham Forest, Aston Villa, Aberdeen, Steaua București, KV Mechelen, Parma, Lazio, Galatasaray, Zenit Saint Petersburg and Manchester City (1 Title).
