Not long before kick-off night, the door of the Atlético Madrid dressing room will open and the players will head along the narrow passageway under the stand with its white tiled walls and line up at the foot of the stairs. There, where the noise from the Vicente Calderón towering above them is clearly audible, they will wait. And then they will climb into the unknown.
Atlético have not been in a European Cup semi-final for 40 years and only two of their players have reached this point before. One is David Villa, the other is Tiago Mendes. It was nine years ago and the memories are not entirely fond ones: Tiago was in the Chelsea team who lost to Liverpool in 2005, thanks to that Luis García goal. "When you go out to a goal when the ball doesn't go in, it's hard to take. It kills you," the midfielder says. "At the time you want to kill everybody but the anger eventually passes."
Petr Cech, Frank Lampard and John Terry were team-mates that night and José Mourinho was his manager. On Tuesday they will be opponents. "I'm looking forward to seeing some old friends," Tiago says. "It was an unforgettable year at Chelsea and my departure was a little sad. It was my decision to leave and it went against what Mourinho and the team wanted, but it was a personal decision. Gérard Houllier wanted me at Lyon: he was ringing me every day and it was a chance to play every week. Things went well for me and Chelsea kept winning."
Tiago has played for Benfica, Lyon, Juventus and Atlético, winning titles in Portugal, England and France. But, he says, what Atlético are achieving now – they are three wins off the league title and three wins off the European Cup – is the greatest achievement of all. He's already referred to them as football's "Robin Hood". He explains: "This is a two-team league and yet if we win three of our last four games we win the league. Not in our wildest dreams could we have seen this scenario."
First, Chelsea. Tiago knows them well. He knows what to expect from Mourinho and how to decipher it. Better still, he knows how to ignore it. Most in Spain anticipate a few tricks. Yet Diego Simeone admires the Chelsea coach and Tiago sees likenesses in the pair, right down to the style. A few minutes before, the captain Gabi had joked that if Chelsea tried to give Atlético the ball "we'll give it back". When the punchline is played back, Tiago smiles in recognition.
"We're comfortable when the other team has the ball. There are lots of similarities between the teams: very organised, very strong from set pieces, which could be decisive," he says. "The coaches only think about winning and that mentality comes through every day." In that sense they're not similar, they are identical.
"Of all the coaches I've worked with, they're at the same level: top coaches. Simeone's mere presence on the touchline motivates us. Seeing the way he lives every minute reaches you; what he transmits to us on the pitch is incredible. Mourinho does the same but in a different way: he motivates you through the week. It's perhaps more mental. With Simeone it is what he expresses, the energy; with Mourinho it's more the way he gets inside your head."
Opponents' heads, too. Perhaps Tiago can ensure Atlético are not affected by Mourinho's attempts to load pressure upon newcomers at this stage. "It's not just me: José was here for three years so we all know him." Were you surprised that things went wrong at Real Madrid, then?
"Yes, I was," the Portuguese says, "because the strength of Mourinho is precisely that – that he has players who are with him to the death. And in Madrid in his last season we saw divisions in the group, when his strength is unity. Mourinho knows exactly what to say to his players in any given moment. He makes the decisions. He never consults the players and never tells the [media]. He takes responsibility, he's the leader and it's a role he plays better than anyone. We all know that if he has to crank up the pressure to win he will do that."
Over Thibaut Courtois, Mourinho has quietly let it be known that he is not happy to see him face the club who own the 21-year-old goalkeeper. "He's a Chelsea player so it's normal that everyone's talking about him," Tiago says. "We've tried to isolate ourselves, because if we're going to win we have to be completely focused. I haven't spoken to Thibaut about it but although he's a kid, he's very grown up. He's intelligent. He's a man: he knows the spotlight will be on but he responds very well to pressure.
"José just wants to win: he knows Courtois is very important for us and he wants to weaken us. Any coach would. [But] it would have been very cruel for Courtois not to play this game. Football itself doesn't deserve for Courtois to miss out. For the good of football we all like the idea of having [Petr] Cech in one goal and Courtois in the other – two wonderful goalkeepers.
"Courtois is the best in the world, as far as I'm concerned. He transmits an incredible security to the team. He's just a boy but you look at him and it puts you at ease. It's impossible to explain how safe he makes you feel. You know he's going to come for every ball, he wins points for us, he's the No1. He always makes that decisive save that turns a game."
For a team like Atlético, treading new ground, that could be vital. As for Mourinho, he reached three successive Champions League semi-finals in Spain – and lost all three. Tiago laughs. "Let's hope it's four."