Liverpool: “It’s hard not to think about it,” Andy Robertson says as he looks forward to the Uefa Champions League final after the Liverpool left-back has reflected on his uplifting story from being a Celtic reject and relegated with Hull City a year ago to facing Cristiano Ronaldo and Real Madrid in Kiev this Saturday. “When you’re lying in bed you just think: ‘What if?’”

Robertson breaks into a helpless smile. He has fought hard to reach this point but the 24-year-old Scot allows himself to enjoy the fleeting anticipation of Liverpool possibly becoming European champions for a sixth time with Robertson as one of their new cult heroes. “That’s natural,” he says during a break at Liverpool’s training camp in Marbella. “Real Madrid have been to three finals in the last four years so they’ll do the same.

“But the head is the worst part of the body because it can let you wonder. It’s about making those happy thoughts a reality. Of course we believe we can win it — but we know how hard a task we face.”

Robertson’s emergence as one of the stories of the season was sealed against a previously rampant Manchester City in the quarter-finals. Liverpool tore City to shreds in the first leg, with Robertson full of high-energy commitment throughout both games, and secured a 5-1 aggregate win. He was then outstanding, home and away, in the semi-final against Roma.

“Everyone is nervous in these games but it’s about using your nerves in the right way. Some people shy away from it but others use the nerves in a very positive way. Against City at Anfield, all 11 of us stood up to the pressure. And in the second game we showed a side we’ve not always shown. After the worst-possible start [conceding an early goal] we defended really well and gave them no chances.”

Amid Champions League fervour he remains grounded and chock-full of amusing anecdotes about how different his life was a few years ago. In 2013, while playing as an amateur for Queen’s Park and working part-time for the Scottish FA at Hampden Park, he would take telephone bookings on the phone for games and concerts. He also worked on match days.

“I once showed Vincent Kompany to his seat,” he says, imagining how bemused he would have been then had he known that four-and-a-half-years later he, rather than the Belgium international and Manchester City captain, would appear in a Champions League final. “Scotland played Belgium and I was told to show [the injured] Kompany to his seat and give him a programme. He won’t remember it.”

Mohammad Salah is the player of the season but Robertson represents another incredible bargain. Having been part of two relegated Hull teams, while winning promotion from the Championship in his middle season, Robertson was signed last summer for an initial fee of £8 million (Dh39.4 million). The response from Liverpool’s supporters was underwhelming. Eleven months later Robertson is an Anfield favourite, alongside Salah, and they share a hospitality box.

“Mo’s family and friends have been lovely to my family. We come from completely different backgrounds but they get on so well. My family got a picture with him when Mo walked in last Sunday [after Salah had been awarded the Golden Boot].”

There are serious points to make about Robertson’s conviction. “I always believed in my ability,” he says. “I just had to work hard and be patient and, yeah, at times it didn’t look likely. You need a wee stroke of luck but every chance I’ve been given, I’ve taken.”

Robertson was cut from the Celtic academy for being too small at 15. “If you’re let go from Celtic, the club you support, and go to Queen’s Park, people think it’s a disaster. I don’t think I cried but I was very upset. As a young boy your dream has been taken away. But I had good people around me and it was probably the best thing that happened.”

Robertson joined Liverpool last July and recalls the impact Jurgen Klopp had on him. “When you meet a new manager you’re nervous and this was even more so because our gaffer is world famous. But he gave me one of his hugs and relaxed me from day one. The gaffer really wants to know you. I sat down with him and he told me about his past and I told him about mine. We both had to battle for everything. He liked my story and that helped.

“Football is full of highs and lows but when people retire they often say: ‘I wish I’d enjoyed it more.’ I’m now playing at one of the biggest clubs in the world in a Champions League final. Of course there’s still that pressure but you need to enjoy it. I will.”