Barcelona's humiliating defeat against Bayern Munich was the culmination of years of sporting mismanagement at the Camp Nou, yet it was followed with Pep Guardiola's Manchester City falling out of the tournament at the quarter-final stage for the third year running.
As a duo, Messi and Guardiola were able to get the absolute best out of each other in the Champions League, and they never suffered the humiliations together that they have been subjected to whilst apart.
Monaco, Liverpool, Tottenham Hotspur and now Lyon have all piled on the pain for Guardiola and his 800-million-euro team, with the coach yet to lift the trophy without having Messi by his side.
Messi, conversely, has tasted continental success without the former Bayern Munich coach, although that came as far back as 2015 in Berlin.
The Argentine was happiest under Guardiola, although he was a lot younger then and had senior players around him, and it's fair to say that the coach was happiest when he had Messi by his side,
At Bayern Munich and Manchester City the tactician has been accused of overthinking Champions League knockout ties, where he couldn't at the Camp Nou because the starting base point was always a 4-3-3 formation which had to somehow include the greatest footballer on the planet.
Messi's contract at Barcelona ends in June 2021 and it's clear he feels a great deal of frustration with the way the Blaugrana are being run, and his future is one of the biggest unknowns in world football.
Interestingly, Guardiola's contract with Manchester City also expires in 2021, which could leave both individuals on the market for a club to take at the same time, reuniting the dream partnership in search of European success.