Boss Brendan Rodgers described Celtic’s 5-0 defeat by Paris St Germain as “humbling” but stressed the need for a more positive Champions League mindset.
The free-spending French side arrived in Glasgow for their Group B opener on Tuesday night with a front line costing more than £400milllion.
And Brazil star Neymar, 18-year-old French sensation Kylian Mbappe and Uruguay international Edinson Cavani all scored in the first half to have the points effectively secured by the interval.
It was a record home defeat for the Hoops in Europe, with their worst away defeat coming at the start of last season’s campaign when they were thrashed 7-0 in Barcelona.
Celtic finished bottom of their section, which also included Manchester City and Borussia Monchengladbach, with three points.
German giants Bayern Munich and Belgium side Anderlecht also await the Scottish champions in this season’s competition and while Rodgers acknowledged how difficult it is to progress into the knockout stages, he is looking for a change in mentality.
“The problems we had in the game were probably more mental than anything else,” said the Northern Irishman, who confirmed striker Moussa Dembele is available after recovering from a hamstring injury.
“It’s the mentality for me. I think for Celtic to qualify for the Champions League is huge in many ways, but that can’t be seen just to be the success.
“I want us to go into the Champions League and then impose our way of playing and way of working.
“I know we’re a million miles away financially from where other teams are at, but it still should allow us to compete.
“Of course that takes a little bit of time to get that mentality across. It shouldn’t just be a celebration of us qualifying.
“We know how huge it is for everyone. We know what it is for the nation to have that representation, but that just can’t be it. And it won’t be. It’s something we’ll learn from.
” That was a humbling experience for them the other night.
“You are playing against that level and quality of team then of course it can be a difficult night for you and it was that for large parts of the game.”
Rodgers claims it was “a pity” that Neymar appeared to refuse to shake the right-back Anthony Ralston’s hand at the end of the game.
“I have spoken about my admiration for Neymar,” said the Parkhead boss. “It would have been nice if he could have recognised the young guy, 18-year-old playing up against himself as a top-class player.
“Maybe if he feels that when he comes to Celtic Park it is a hostile ground, a difficult place for him to come so the friendship isn’t quite there.
“But it would have been nice for him to acknowledge the young guy because he (Neymar) is a sensational player and that sort of mark of class is when those high level and elite players can show that bit of humility afterwards.”