How often can one see Lionel Messi on the bench?
Also, how often can one see 'La Pulga' biting his finger nails in anxiety while watching his Barcelona teammates battling to win a match?
This happened in Barca's Champions League return leg clash against big spenders Paris Saint-Germain at Nou Camp on Wednesday.
Messi would have loved to start the game and help the Catalans advance to the last four for the sixth successive time but sadly, the 25-year-old ended up on the bench as he had not recovered fully from the hamstring problem suffered in the first leg in Paris last week where he scored once in the 2-2 draw.
Without Messi, the Catalans were struggling in front of more than 90,000 fans against PSG who looked more dangerous in the first half.
Only Andres Iniesta, Pedro and Victor Valdes were performing up to their expectations, really.
Barca were so poor that PSG could have killed off the tie in the first 45 minutes.
The Barca midfield was not functioning well, the well-calculated passes were missing as they struggled to penetrate the PSG defence.
The Catalans' defence, as usual these days, was shaky in coping with PSG counter-attacks.
Then the French side deservedly took the lead five minutes after the break through Argentine Javier Pastore.
Messi was restless on the bench after this setback. He was looking worried as the TV camera focused on him. And he was even biting his finger nails.
Barca manager Tito Vilanova knew it was time to take a risk by sending Messi on the pitch. He also knew that this little genius could well be the saviour of the team despite being injured.
Messi came on in the 62nd minute taking over Cesc Fabregas and things changed almost instantly as Barca began to produce some deadly moves.
Psychologically, the presence of Messi also affected both his teammates and opponents.
His teammates' confidence was back.
PSG, who were enjoying themselves earlier, began to rattle because they knew what Messi could do to shatter their aim of making the last four.
And in the 72nd minute, it happened when Pedro struck from a superb effort to make it 1-1 and Barca advanced to the last four on away goals ruling.
It was Messi who initiated the crucial move as he relayed the ball to David Villa who then set it up for the waiting Pedro.
Messi had done his job ... and he was half fit at that. Things would not have been difficult if only he had started the game.
Yes. He made an impact.
This only shows how vital Messi is to Barca.
A journalist then posed an interesting question Messi's father Jorge. He asked: “Can the wizard cope when Messi’s physical pace wanes later in his career?”
Jorge said his son can adjust his game as he gets older.
“When he is not as quick (in the future), he can play deeper, in front of the defence, as a playmaker,” Jorge answered.
“He is already doing this from time to time, when he often starts moves from the back.”
And El Loco believes Jorge. Of course, Leo can play as a playmaker, just look at his penetrative passes.
Barca joined Real Madrid, Bayern Munich and Borussia Dortmund in the last four with the draw being held on Friday.
The significant factor here is that the four semi-finalists are from Spain and Germany - two each from each country.
And the irony is that Spain are on top of the Fifa ranking released on Thursday with the Germans second.
Many say Bayern are now favourites to win the title this season. Let's see if the German giants can make this a reality.
Real are performing well as well with Cristiano Ronaldo in great form while Barca need to improve their defence to have that chance.
One of the two Spanish giants can triumph in the end.