YOU could forgive Pep Guardiola for feeling the heat.
When Jose Mourinho's appointment was confirmed by Real Madrid there will have been a slow burn moving inside the Barcelona coach.
Perhaps a loosening of that infamous slim-cut tie. A wipe of the brow as a bead of sweat escaped the effortlessly cool exterior of Senor Guardiola.
His mind would have wandered back to early April, to the touchline on a humid night in boisterous Barcelona.
As chants of Forca! Forca! Forca! rang out across the ground he'll have remembered that sinking feeling as Inter Milan put backs against the wall, hired double-deckers and parked them in concrete graves along their 18-yard box.
From the corner of his eye he'll have seen the smirk. The wagging finger of the greatest football psychologist in a generation as he bounded towards him. He can still hear Mourinho's teasing, arrogant, sneer of “it's not over yet…”.
The Special One was revelling in the mire. He had come to the temple, not to worship, but to burn it down. And he succeeded. There was nothing, not even the charging fury of a last-gasp stab in the dark from Gerard Pique, that could stop him.
It was a personal defeat as much as it was one for club and country. A footballing philosophy had been toppled by it's nemesis across the bridge, the old darkened brigade had taken what Barcelona had long considered their birthright – the throne atop the Kingdom of European and World football. And they had done it the “wrong way”.
As Mourinho danced across the turf of the Nou Camp, fists pumping as he hailed another impossible victory, the sprinklers set off by bitter Blaugrana officials did little to dampen his spirits.
And here comes the bad guy once again. Like Darth Vader leading a fresh fleet of billion pound Stormtroopers there's still a fair chance planets might explode when these two rivals meet tonight.
And he'll be expected by his own high command, the Los Merengues faithful, to deliver another crushing blow.
The real questions is: Has Guardiola learned anything? Does he now know how to cope with a stubborn Mourinho who will refuse to play the same game? Will he change his own attitude and employ cut-throat tactics to defend against a Real Madrid side who are even better than Jose's Inter?
Short and simple, the answer is “no”. Barcelona play one way, rain or shine, defence and attack. Guardiola may know he's playing with fire but he's prepared to wage watching his dream of three La Liga titles in a row going up in flames to prove his point this term.
Pep has already beaten Mourinho, not that it mattered, at the San Siro in group action last year. It's not impossible to see it happen again tonight but there was a great difference in those Champions League semi-final games.
Always learning, adjusting and transforming, the malleable management of Real Madrid's manager seems to ensure defeats are merely lessons on the road to making him even stronger.
When both bosses empty the toolbox they're equally impressive. You could debate all day over a combined XI but the focus will be on two outstanding talents in Cristiano Ronaldo and Lionel Messi.
Both have stunning goalscoring records, in Spain and in continental competition, both are capable of turning the tide of any match.
Messi is unique in that he seems to be naturally gifted rather than the chiselled work of hours spent on a training ground.
This isn't entirely true, of course, as the little Argentine works just as hard if not harder than anyone in football.
At 23 he's already the talisman for one of the world's biggest clubs and for his country. Terrifying speed, incomparable dribbling ability, architect and finisher of nearly everything Barcelona put together, he's without doubt one of the best – if not the best – players on the planet.
Ronaldo is as close to physical perfection as you'll see in sport. Height, weight, stamina, speed and drive are married with phenomenal skill and brute force.
His approach to the game is different from Messi in that he's explosive in everything he does. Lung-bursting runs and finger-snapping shots mean he's usually anything but subtle, although it's not at the cost of precision or creativity.
His tricks and flicks, heading prowess and consistency in front of goal mean he'll be chief warrior again for Mourinho.
But you really want to know who's going to win, right?
Real come into the game unbeaten this season but haven't won El Clasico since May 2008.
Truthfully, there's nothing in it. I have a fear it could be a cagey 0-0 draw and the bookies are offering 14-1 (Stan James) on that being the case.
Mourinho has hinted at playing a 4-3-2-1 formation, bringing in Lass Diarra for Mesut Ozil, with the idea of suffocating Barca like he did on his last visit.
Having failed a late fitness test, Real will be without Gonzalo Higuain which is a big blow to their chances. David Villa (2-1, boylesport) should start for Barca, though.
If you're sitting on the fence when it comes to goals, going with over 1.5 goals could prove to be among the safer bets. If Barca or Real score you'd figure the other will push forward. For both to net look at 4-6 with Skybet.
- Ronaldo to score (7-5, Paddy Power)