Arsenal and Chelsea take on Valencia and Eintracht Frankfurt respectively on Thursday night in the semi-final of the Europa League with the chance to emulate Liverpool and Tottenham Hotspur who both reached the Champions League final after spectacular comebacks.
No country has ever provided all four teams for the finals of the two leading European club competitions.
Liverpool reached the 2019 Champions League showdown in Madrid on 1 June after routing Barcelona 4-0 at Anfield in the second leg after a 3-0 defeat at the Camp Nou on 1 May.
Tottenham's pyrotechnics on 8 May came in Amsterdam after Ajax led 3-0 on aggregate. Lucas Moura was the Spurs hero with a hat trick and the north Londoners advanced on the away goals rule.
Arsenal will therefore feel queasy with a 3-1 advantage at the Mestalla after the first leg at the Emirates on 2 May. Alexandre Lacazette bagged a brace and Pierre-Emerick Aubameyang scored the third to provide what used to be considered a decent cushion.
"We played against two strikers that are very good which is why they cost the millions that they did," said Valencia coach Marcelino Garcia Toral after the first leg. "With the slightest error they punish you."
Arsenal need to progress to the final and win the trophy in order to play in next season's Champions League. Last weekend their fluffed chance of reaching the competition via their position in the Premier League due to a 1-1 draw with Brighton.
Valencia also have motivation. They are three points off the Champions League slots from La Liga with two games remaining.
Arsenal's draw coupled with Manchester United's stalemate at Huddersfield allowed Chelsea to seal a spot in next season's Champions League. Maurizio Sarri's side will finish third if they mirror Tottenham Hotspur's result in their final games of the season.