Brendan Rodgers has promised Celtic supporters that his team will put up a better fight against Manchester City than they did in the heavy loss to Barcelona.
But the former Liverpool manager concedes that the club’s two year absence from the competition has left Celtic playing catch-up.
The Hoops host Pep Guardiola’s English Premier League leaders on Wednesday, a fortnight after being condemned to their worst ever defeat in European football in a 7-0 mauling in the Nou Camp.
Celtic manager Rodgers, speaking to the BBC, said: “Pep has done brilliant since he’s gone in there, he’s got some world class players.
“He’s honed them really quickly into a real, aggressive team and they’ve started the season really well.
“We know the size of the task but one thing for sure is that we won’t be as passive as what we were in the Barcelona game, and hopefully we can be much more aggressive in our play.
“The Barcelona result wasn’t so much damaging, many words can describe it.
“As a professional there is a little bit of humiliation in it.
“No matter how good the team are, it’s still very difficult to accept. There was that low feeling but very quickly as a coach, management and staff, you have to bring the players back into reality.
“We had come off the back of a great performance and result in the Rangers game and then we go within a matter of four days of being on a real low because of that Barcelona experience.
“So my job is to stabilise all the emotions that have gone on between the two games and then just ensure we can be better for that experience.”
Celtic have returned to Europe’s elite competition for the first time since the 2013/14 campaign, and with so much prize money at stake in the Champions League, Rodgers concedes that the gulf with the leading clubs on the continent has got bigger.
He added: “Similar to the Premier League, the Champions League gets better every season and when you haven’t been in it for a few seasons, then it can be tough when you first get back in.
“The idea is to be in it as much as we can, that allows the club to grow and that allows your playing staff to grow. That allows you to improve the quality but that will take time.”