Real Madrid manager Jose Mourinho has been tested on many occasions throughout his career.
But tonight's Copa del Rey final against Barcelona at Valencia's Mestalla Stadium might be his greatest moment to shine.
How much of a role does a manager play in the result of a match?
Mourinho can shed some light on that question. The Special One has a talent-rich squad, but he is facing the most cohesive club in the world.
Barcelona has excellent players at every position, but it is their chemistry that separates Barcelona from the rest of the elite clubs. The Catalans drive opponents mad with their fantastic ability to maintain possession of the ball.
When their opponents eventually regain possession, they often look out of sorts, after spending so long chasing it.
It will be up to Mourinho to find the right tactical arrangement to counter the passing style of Barcelona.
He already basically had a tune-up match on Saturday. In a 1-1 score, Mourinho sat Mesut Ozil, perhaps the best play-maker in the world, for most of the match.
Tonight, Mourinho can use the knowledge he's learned from the 5-0 thrashing in November, and the 1-1 result on Saturday, as gauges for the Cup Final. He will be without Raul Albiol, who is serving a suspension.
For the most part, both teams are healthy. On a neutral surface, there will be no excuses for tonight's results.
Ozil, Cristiano Ronaldo, and Sergio Ramos must play at their best. Should Ronaldo convert, or at least put pressure, on Victor Valdes, the momentum may swing to Real Madrid.
A confident Real Madrid team may force Barcelona do to something they don't want to do, like foul. Barcelona want to limit Real Madrid's set-piece opportunities. Ronaldo is capable of fantastic goals on free-kicks, and the match may come down to well he executes them.
Also key for Real Madrid will be the right and left backs. Containing David Villa and Lionel Messi is always a challenge, and Real Madrid has to have an effective off-sides trap to get the ball back from Barcelona after one of their long possession spells.
Mourinho has to make sure his club doesn't make dumb mistakes. There is little margin for error when playing Pep Guardiola's squad. Though, Barcelona certainly can be beat as Arsenal proved in February.
Perhaps Mourinho can feel good going into the match knowing he has luck on his side. Iker the Octopus picked Los Galaticos to beat Barcelona.
PREDICTION: Barcelona will push hard in the later part of the first half, but Real Madrid defenders Ricardo Carvalho and Marcelo will slow them down. The Barcelona midfield will tire towards the end of the match, and Real Madrid will surprise the Catalans with a late goal, and hang on for the victory.
REAL MADRID 1, BARCELONA 0.