THE hand of Jose Mourinho will be subtly guiding his former players when Chelsea embark on Operation Block Barça here in the Nou Camp tonight.
Mourinho has sent messages to his old charges, wishing them well in this seismic semi-final, and the current coach of Real Madrid hopes to see them in the Munich final of the Champions League.
These are Roberto Di Matteo's chosen ones, but he shapes a side from human clay bequeathed by that Rodin of team-sculptors, Mourinho: Petr Cech, John Terry, Frank Lampard and Didier Drogba. Mix in the enduring dynamism of Ashley Cole and another Mourinho team chase down Barcelona, just as his Madrid side did on Saturday; just as his Inter Milan team did two seasons ago.
When the Special One departed the Bridge, it always felt that he left a mission statement behind, something in the players' DNA that made them ready for occasions like this. Defiance. A streak of negativity. Fascination with the referee. Some mind games. Terry. Drogba. Those two names will define tonight's game. If Terry organises Chelsea's defence to frustrate Lionel Messi, Di Matteo's side have a chance.
If Drogba shakes off his apparent knee complaint and starts, so running Barcelona's backline ragged and running down the clock, then Chelsea have a real chance.
Leading through Drogba's well-taken first-leg goal, a stalemate sees Chelsea through. Di Matteo's players stayed on last night in the elegant Rey Juan Carlos I hotel near the ground, warmly greeted by fans, and it is to be hoped that the defenders in particular enjoyed a good night's sleep. They will get no rest tonight. Not with Messi about.
All's fair in love, war and big-match mind games, and the news was leaked that Messi was a doubt for this match, just as Drogba was supposedly struggling. Come early yesterday evening, Pep Guardiola's players strolled out for training at the Nou Camp. There was Gerard Piqué.
There was Carles Puyol. There was Xavi and Andrés Iniesta. It was like a dream Panini sticker album.
Simply the sight of Messi reminded all who wish Chelsea well that this was more than a club, more than a test. The standards here are so high: Messi has failed to score for two games and people are questioning him. Hilarious.
Fortunately, Guardiola was around to introduce some sanity to the debate.
"I can never be worried about Messi, even if he goes 27 games without scoring a goal," said Barcelona's admirable coach. "One day he scores three goals, the next day he gives assists and creates chances. We have to give him permission not to score.
"Of course, he likes to score. He feels responsible for his part in our attack. His leading role has helped us achieve all we have. But it is never easy against a team that puts nine or 10 players near the area."
So Messi runs into the barricades of blue again. Chelsea require another masterclass in the defensive arts from those on their payroll. Gary Cahill came through some early scares in the first leg.
Terry was superb. Ditto Cole. Branislav Ivanovic played his part.
"We're very pleased with the way our defenders have been playing lately," said Di Matteo.
He will need his midfield, including the likes of Lampard, John Obi Mikel and Ramires, to form a shield.
When Di Matteo played here in 2000, eventually losing out to Guardiola, Chelsea swamped midfield with Dennis Wise and Jody Morris also in there.
"It's a long time ago, a different team,'' Di Matteo shrugged. "Our team today is much stronger than that one." So is Barcelona's.
"Our first and fundamental principle is based on kids playing the ball around and having fun," said Guardiola. "That's never going to change. The ball is the master of everything. I have faith in my players in good and bad times. Whenever you suffer defeat, you feel a bit low but afterwards you gain faith from analysing the facts. We are talking about very experienced players who have faced these kinds of situations many times before."
Guardiola is convinced Barcelona will respond to his advice and the supporters' urging.
Barcelona will score. So Chelsea will need to take one of the few chances that they can conjure, whether from a set-piece or a lightning break like the one Lampard and Ramires brilliantly created for Drogba last Wednesday.
"I do think we'll have to try and score a goal," said Di Matteo. "It'll be difficult just playing for a goalless draw."
He did not promise a sudden reversion to the Beautiful Game. To those decrying Chelsea's conservative football, Di Matteo countered: "You have to use the strengths of your players, and see what the weakness of the opposition is."
Di Matteo observed that he would decide today whether Drogba or Fernando Torres would start. Drogba has to. Barcelona have a fixation bordering on fear of the tall, tumble-ready, goalscoring Ivorian.
Di Matteo was more forthright about those on a booking, those such as Ivanovic, Cole, Ramires and Raul Meireles.
"I don't think we can be thinking about that,'' he reflected.
"The players will be playing fully focused on their task and their responsibilities in the game. We cannot speculate on the bookings."
He sounded confident. "We need away from home, as we've seen in the past, a bit of luck to do well in a competition like this. But the quality and the squad we have at Chelsea is very good."
Once again, Di Matteo avoided talk about his future, emphasising "it's quite irrelevant ... at this point".