Celtic manager Martin O'Neill admits the 3-0 Premier Sport Cup defeat to Rangers was an "eye-opener" for some recent signings, adding that "defeat should hurt", as they prepare to face Ferencvaros in their opening Europa League fixture on Thursday.

Celtic return to the European stage after failing to overcome LASK in Champions League qualification before hosting Rangers again on Sunday in the Scottish Premiership.

"The whole idea of trying to win the league is to get into European football," O'Neill explained. "We were hoping that we might have been Champions League, that was a disappointment. But the Europa League is still very strong. We'd like to get off to a decent start if we could.

"There's clearly a lot of disappointment at the weekend [against Rangers]. Every game that Celtic lose, there's a crisis. Of course, it's even bigger if you lose to Rangers."

Five of O'Neill's starting XI were playing in an Old Firm match for the first time and O'Neill said: "I think it was an eye-opener to some of the newer lads.

"So you've got to find out about players, about whether they're capable of dealing with these games. Hopefully, over the course of time, they will be. They should hurt. I think [for] some of the newer players, it was a revelation in many aspects.

"We disappointed ourselves, we disappointed the fans in the game and we just have to rise to the occasion. But we've done it before. We'll get ourselves right."

On paper, Celtic's match-up against Ferencvaros looks like one they would look to capitalise on given the strength of some other sides they will face.

O'Neill, though, was keen to stress that they will not take the opposition from Budapest lightly. "I think any side playing in European football will provide us with problems and we just have to try and overcome them," he explained.

"We've found a way to win in the last season. We found somewhere along the way when the odds were piled against us.

"Now it's up to us to try and push on from there. The season will be tough. Tomorrow night will be tough. Sunday will be very tough as well. It's up to us to find ways to try and win football matches regardless of who plays.

"They have about three lads on the side who are exceptional footballers, exceptional players, and they will cause us lots of problems. But we hope to be at home, try and get the crowd on our side as much as possible and try and win it."

O'Neill conceded he may makes changes to his side given the demands of facing Rangers either side of Ferencvaros and the intensity of their schedule overall.

Duran is fit and available after a visa-related visit to London following a call-up to the Columbia national side, with questions over whether he may be best suited to playing as a central striker given his return early this season in that role.

Alex Oxlade-Chamberlain is suspended while fellow midfielder Joel van den Berg and on-loan Chelsea forward Shim Mheuka are not in Celtic's Europa League squad.

Winger Yang Hyun-jun is on international duty with South Korea at the Asian Games.