It was the Premier League's opening day and Norwich City were visiting Anfield. Liverpool's Alisson was down with a calf injury. There was silence in the stands.
Jürgen Klopp brought his new substitute goalkeeper off the bench and spoke softly in his ear: "Welcome to Anfield."
Adrian had only been at the club for four days. He had trained with his team-mates just twice. As he was about to make his debut, did Klopp have anything else to add?
"He hugged me. He showed me I had his trust," Adrian says. "I felt like the schoolboy who has to introduce himself in front of his new classmates, but what can I say about Anfield? The way the fans embraced me in such a critical moment, losing one of their best players. They gave me total confidence."
Adrian smiles as he looks back now on that unexpected Anfield bow - and the whirlwind week that followed. The Spaniard, 33, is enjoying life as the guy who landed on his feet in Liverpool half a year ago.
But to really understand him - and how he fits in to a very special team - you have to go back a little further still.
Things might have turned out very differently for Adrian. For a long time it seemed as if his time might never come. After years spent waiting in the wings, he finally made his debut for Real Betis, the club he joined aged 11, when he was 25.
He also came off the bench that day, in the 11th minute, dressed in yellow, with the number 13 on his back, which is also a sign of bad luck in Spain. He conceded four goals before the final whistle in a 4-0 defeat by Malaga on 20 September 2012.
A few months later, there was another low point: a 5-1 thrashing by city rivals Sevilla.
But Adrian was never going to give up, and the confidence of his manager - former West Bromwich Albion boss Pepe Mel - helped him through.
"I often think about that match," Adrian says. "It was one of my career's key moments. Pepe was the first manager to give me a chance as a professional.
"He trusted me beyond any mistake I could have made that day. A week later we beat Real Madrid 1-0 at home, and I stopped several goals. Man of the match. Kind of. Since then I've improved a lot. I'm very grateful to him."
At the end of that 2012-13 campaign, with 32 games under his belt and with Betis struggling financially, Adrian would move on. The Premier League was his next destination. He packed his bags and left for West Ham United as a free agent. And he would keep that number 13 shirt.
For a 26-year-old Andalusian who had never been abroad and spoke only in his mother tongue, it was the start of an adventure that would bring much joy, but also disappointment. Towards the end of his time with the Hammers he had lost his starting spot, and with his contract up last summer - having made 150 appearances over six years at the club - he was once again free to move on.
Without a team, he spent pre-season training alone in Pilas, on pitches used by a local non-league side, 30 miles away from his hometown of Seville. It was anything but easy.
"I'd made a drastic decision not to stay any longer at West Ham, despite having a three-year contract offer on the table," he says. "I hadn't played a single game all season in the Premier League. I didn't feel valued economically either, to be honest. It was tough for me.
"Summer came and then I felt those butterflies in my stomach. I knew something good was coming. I was already aware of Liverpool's interest before I received the first offers.
"They called me at the end of July. They said that they'd sell [Simon] Mignolet if I gave the deal the green light. That's how it happened."
Real Betis might have been in for him too - Adrian even fantasised over the idea of making a return - but there was uncertainty following the departure of Quique Setien, now manager at Barcelona.
"It could have worked but the new staff still had to decide what kind of keeper they needed," he says. "In the end, they signed a much younger player. I didn't fit their profile, but we're professionals no matter what we feel inside. My final decision wasn't that bad after all, was it?"
Adrian laughs. He is a man who laughs often. And right now there is a lot to laugh about in the Liverpool dressing room. Their 22-point lead will surely lead to a first league title in 30 years. But nobody's talking about how close they are, not even the man most responsible for Liverpool's remarkable recent success.
"What Jürgen has achieved here is extraordinary," Adrian says. "Just look how we are in the league. It is so easy working with him. So easy. He's always smiling, cheerful, optimistic. He's the manager but he behaves like any another member of the team.
"Him being close to us helps us believe in his methods. He's convinced us all of his leadership and abilities by being close to us and proving that whatever is on his mind works in the end.
"Klopp usually tells us that we'll face many problems during the games, so we must be able to fix them. Any team can surprise you with a new system, for example. He's there to guide us. He visualises football very well from the sidelines and transmits this knowledge to the players in a masterful way.
"Training sessions are intense. He does his job passionately and that's exactly how we perform on the pitch. Jürgen is not only a top strategist, but also a great person. The best group management I've seen. Next to the team through thick and thin."
For Adrian, too, this has been a remarkable season. After having not played a single game last term and after a summer spent training with a friend on non-league pitches, on 5 August it was announced he would be signing for Liverpool. His Friday evening debut came four days later and then, five days after that, came the Uefa Super Cup final win over Chelsea.
In just over a week Adrian went from zero to penalty hero - and, in doing so, won the first title of his career.
The Super Cup win was celebrated in Seville as well - in Su Eminencia, the working-class neighbourhood where Adrian was raised.
"Everyone met at my parents' house - my wife, my closest friends, my in-laws. Everything happened so fast that they didn't even have the chance to fly to Turkey for the match, we couldn't arrange it. Receiving that video call and seeing tears of happiness from home was unforgettable."
Later that night in Istanbul, with almost the whole team sleeping, Liverpool's leaders made their first proper gesture to fully welcome the 'new guy at the office'.
"James [Milner] told me to take the trophy with me for the night. It took me several seconds to realise he really meant it. Who better than me, he said. So I agreed."
Adrian's brother and a close friend, the only people close to him who were able to come, were waiting in the hotel upstairs.
"Getting into the room with the Super Cup, my first title. Their faces. Awesome."
When he signed for Liverpool last summer, some Spanish media talked about Adrian as a washed-up, discarded 32-year-old. He of course did not see it this way. He resolved to do his talking on the football pitch. He just had not expected his chance to come so quickly.
"It was a moment I was hungrily waiting for. Not so soon, though," he admits.
"Fortunately, I was both mentally and physically ready. I had to see it that way. It's never pretty when a team-mate gets injured, but only one of us can play.
"Alisson is peaceful, humble and deserves every single thing he has achieved. We spend so much time together, but still I'm here to fight. I won't just sit down on the bench and wait.
"He won the Champions League and the Copa America last year. He was the best keeper in the world. But he can't relax with me around. I've proved it."
At Liverpool's Melwood training ground, the skies are darkening and the wind is howling. Adrian begins to look at the clock on the wall, then on towards the training pitches outside. He cannot take his eyes away. It is clear he is already thinking about getting back to work - his body language betrays him.
"Hey, Ali!" he shouts as Alisson walks past. They smile at each other. A few seconds later, young midfielder Curtis Jones walks through the door and gives him a fist bump.
Now the hallways are beginning to buzz. It is time to get going. There is another hard session ahead, another challenge to prepare for, more titles to target. Beyond that, Adrian has not thought about much.
"Let me enjoy the moment!" he complains in jest, laughing again.
"Football careers are over so quickly. We have to make the best of it while it lasts."