IT is an afternoon in South London and a teenager is consumed by nerves as he paces a sideline, watching his side take on Chelsea.

Aaron Doran, four days beyond his 18th birthday, has been told he is coming on against the pride of Stamford Bridge for Blackburn Rovers. "We were fighting for relegation under Sam Allardyce; I came on just before half-time but we ended up getting beat," he says of that fateful day of May 17, 2009.

"I was up against Ashley Cole, which was a bit of a learning curve for me and I think I was going backwards for most of the game trying to chase him."

The memory of his reaction when he was told he was going on lingers in the mind. He hopes it will sustain him when he marches out for Inverness Caledonian Thistle against Aberdeen in the League Cup final at Hampden on Sunday. "I nearly fainted," he says. "I'm only joking, I wasn't that bad, but it was good experience for me playing in the Premiership.

"The nerves are part and parcel of the game and there would be something wrong if you didn't feel a bit nervous. There was a lot running though my head that day at Chelsea and I am sure it will be the same at Parkhead but I will be better at dealing with it."

His experience of games past contrasts with another 22-year-old at the club, Nick Ross. His intervention as a substitute in the League Cup semi-final was dramatic, even unforgettable. On February 2, Ross entered the fray at Easter Road with his side 2-1 down. As time was running out, Ross pounced on a ball inside the area and scored the equaliser. Nine-man Inverness went on to win in a penalty shootout.

"When I knew I wasn't playing I felt pretty low as I had played every game up to then," says Ross, a product of the club's youth programme.

"Once I came on there was only a couple of minutes left and I wanted to get a few touches. At least you know you have been involved in the game if you touch the ball and I managed to get a goal. Once I scored I thought it was going to be a long 30 minutes in extra-time."

Yet they survived without resorting to desperation. "As we scored so late it gave everyone a boost," says Ross. "We were just running on adrenaline, I don't know how some of the boys were still running.

"I came on and I felt like I had played the whole game after about 10 minutes with all the running we were doing. We had to defend well and luckily we got through it."

But Ross has a memory of another game to take him into the trials of Celtic Park on Sunday.

On April 20, 2003, an 11-year-old Ross came on in the Scottish Cup semi-final defeat to Dundee in the Scottish Cup semi-final at Hampden. He scored then, too, Ross, though, is quick to point out the precise circumstances.

"I played on the pitch at half-time," he says. "We won and it was a good time as I had my family there. Once I scored I was trying to find them in the crowd, but we had a lot of fans there and I pointed to where they were and hoped they saw it. I remember waiting to go on and being a bit nervous."

The tension will be considerably more acute on Sunday. Both Ross and Doran are part of a squad that have been faltering of late and now they face an Aberdeen side who are overwhelming favourites to win the cup.

They are not daunted by the prospect, though. Doran, a veteran of three top-flight appearances for Blackburn, is spurred on by the observation by Allardyce that the player was "going backwards" before he left England and signed for Inverness, first on loan and then on a permanent deal in 2011.

"It hurt when I saw that article," says Doran who jokes that his upcoming driving test may cause more nerves than a mere game of football.

He and Ross both believe that the pressure is on Aberdeen, who are coming to Glasgow with a support of 40,000 but with a recent history of under-achievement in the cup.

Their history tells them that they have the strength to prevail in spite of the odds and against all predictions. "I have touched the trophy that is as far as it has got," says Ross in the shadow of the League Cup on the club's media day. "I am not holding it up high but it is a dream to do that."

Reality beckons for the boy who scored at Hampden and the teenager who faced Ashley Cole. They are ready to face it.