Andy Walker believes Celtic's valiant defeat to Barcelona can inspire them in the reverse fixture next month and boost their chances of qualifying for the knockout rounds.
Neil Lennon's side were denied a hard-fought point at the Nou Camp by Jordi Alba's 94th minute winner on Tuesday night but sit second in Group G at the halfway stage.
Walker believes Celtic's home support will motivate the team to produce another courageous display when the sides meet again on 7 November in Scotland and, whatever the result in that encounter, feels his old side can pip Spartak Moscow and Benfica to the second qualifying spot.
"You should never write Celtic off in Glasgow," he told Sky Sports News.
"Celtic Park is a special place on Champions League nights. For Celtic supporters this is the highlight of the season for them and they will put on a terrific show.
"The noise level here in a couple of weeks will be the best there is in Europe on that night and Celtic always have a chance at home against the best. The supporters put an extra yard onto the stride of the players and the team have shown in recent years that they are capable of the most extraordinary of results.
"It's going to be a fabulous occasion.
"Celtic may well get beaten by Barcelona again but I don't think we should get too upset about that - it is Barcelona after all - but Celtic are still very much in the group.
"We have to remember they were fourth seeds in the group so, at the halfway point, to be in behind Barcelona in second spot, ahead of Spartak Moscow and Benfica, it has given them a real chance of getting into the knockout stages, and that would be extraordinary.
"Scottish football needs a lift and I think Celtic showed at the Nou Camp they are capable of getting some big results. It's great for Scotland, it's great for the SPL and now we can look forward to the next few games in the group."
Reflecting on the performance in Spain, Walker praised Celtic's defending and said they were unfortunate not to come away with a point.
"It looked as though Celtic were going to take an unlikely point," he said.
"I thought they played a lot of good stuff, were disciplined and defended very well, which of course you have to do in the Nou Camp. But it was so painful to see that goal go in with 30 seconds remaining.
"They denied Barcelona a lot of space - as much as you can do against players of that quality - and I thought it was a very disciplined performance.
"As wonderful a player as Lionel Messi is Celtic kept him relatively quiet and Fraser Forster came up with a couple of wonderful saves.
"You have to have players whose concentration levels are first class when you go to the Nou Camp and that's what we saw from Celtic. But of course Barcelona are so talented."