“It was one of the best moments of my career. Scoring a winning goal against Barcelona. You know, you don’t get anything for it. You’ve only got the memory. But it’s up there, yeah…it’s definitely up there.”

Alan Thompson’s mind has gone back to Glasgow, to a late winter’s night when his name resonated loudly around Celtic Park. The Englishman, a significant cog in Martin O’Neill’s Celtic side who considerably restored what had become a battered European reputation, had latched onto a perfect knock-down from Henrik Larsson to hit a half-volley into the net.

It would prove to be the only goal of an ill-tempered UEFA Cup tie game against the Catalans, a game that saw Rab Douglas and Thiago Motta sent off after an altercation in the tunnel at half-time.

READ MORE: Rodgers reckons glamour Barcelona tie will be ideal preparation ahead of Astana rematchGlasgow Times: Alan Thompson was frozen out at Celtic

On the back of a previous season that had taken Celtic to Seville, Thompson’s goal in March 2004 against an in-form Barcelona side that held the impervious Ronaldinho, Xavi and Carles Puyol was enough to settle this UEFA Cup tie.

O’Neill’s side held on in the Nou Camp to progress to the quarter-finals of the tournament, where Villarreal would subsequently put them out.

This weekend does not compare. Any niggle between the players might well be put down to lack of fitness and sharpness and while a friendly game can be dressed up and lauded loudly, it remains what it is; a game with little at stake.

As Thompson reflected on nights in which Celtic were building a reputation as formidable opponents in a European context at home after a spell in which they saw off some of Europe’s heavyweight on their own soil, he neverhteless believes that Saturday evening’s game in the Aviva has to be taken seriously by the Hoops players.

“I know when I was a player you would look at a game like that and decide for yourself what you wanted to get out of it,” he said. “You’re playing Barcelona. It might not be a full strength, fully fit Barcelona, but it is Barcelona nonetheless.

“And when you play for Celtic it does not take you long to get the message that every game counts – friendly or not. I remember one season in America where we had a poor pre-season and came off a couple of poor results – we were absolutely hammered by the press.

“They had us in crisis before the season even started!

“But I do think that when you play for Celtic, you play for pride. If you fancy yourself as good enough to get into the Champions League then these are the games when you need to show that you’ve got something.Glasgow Times: 27/04/12.CELTIC TRAINING.LENNOXTOWN.Coach Alan Thompson casts an eye over training.

“You get yourself into the hat for the draw and it is a great feeling. First of all you are always looking to see if you get Barcelona or Real Madrid. For some reason, Celtic and Barca seem to be paired relatively frequently in the competition – maybe it’ll be Madrid this season if they get through.

“But, in all seriousness, it is always good to get a glimpse into how a team like that sets up and how the players go about their business. I don’t know that Lionel Messi or Luis Suarez will play, but even still it is a decent game to play.

“It should set them up for next Wednesday’s second leg against Astana.”

Celtic looked to have left the door to the play-off stage of the competition ajar with the crucial away goal that they claimed in Kazakhstan courtesy of Leigh Griffiths. It tilts the tie in their favour ahead of next weeks’ second leg and Thompson expects them to see it out.

However, like many he believes that there is still work to be done as Celtic look to get back to a level where they are comfortable playing amongst Europe’s premier teams.

Kolo Toure is set to feature for the Parkhead side in the return leg, a player whom Thompson faced as a player. He expects the former Arsenal, Manchester City and Liverpool defender to bring stability and composure to what has been a notoriously fragile defence, but he will also expect another few to follow him through the door.

“I think they still need a couple, but I have to say that I thought it was an excellent result over there,” he said. “It is so difficult on the road to get a positive result and I feared the worst for them when they went a goal down.

“It showed a fair bit of character to dig in and get something, so I think that bodes well going into a European campaign. You need to have a bit about you. You need to be a bit streetwise too when you’re playing in Europe.

“Sometimes you lose a goal and you feel the game slip away, but I thought they did well to get that draw. Toure will be good for them. He’s experienced, he’s calm, he’s got a presence but I think they would fancy that they could need one or two more.”

And Thompson would love the Celtic support to be indulged with another Champions League campaign.

“Those nights are incredible,” he said, “They’re special.

“It’s such a stage to be on. They really live with you and you appreciate them more in lots of ways once you stop playing. But the stadium is so alive. You can feel just how much it means to be the club and to the supporters to be in there and in that company.”