The Parkhead club, who reached the last 16 of the Champions League in the last two seasons, are still smarting after their 2-1 defeat at the Energi Nord Arena left them bottom of Group E on two points and without even the consolation of a UEFA Cup place.

Caldwell, whose own goal three minutes from time sealed Celtic's fate after Barry Robson's opener had been cancelled out by Caca's deflected strike, is looking for another SPL title win to ensure another tilt at Europe's premier club competition.

"We know this competition is amazing and it has been good to us for the last two years", the Scotland defender said.

"We have to be in there again next year.

"So we have to pick ourselves up and win the league.

"We have to make sure we make it four in a row in the SPL and then come back stronger.

"But it's difficult. The Champions League is a hard competition.

"We can't just expect to walk in every year and be in the last 16. We have to earn that right.

"This year we haven't done enough to earn that right. But to not even be in the UEFA Cup is a huge blow."

Celtic have gone 18 group stage games away from Parkhead without a win and Caldwell admits a great chance to end that poor record was lost against the Danish side.

He said: "There is no doubt we let slip a great opportunity to win a game away from home.

"You've never done enough at 1-0 but the way the game was going, we all felt that, if any team was going to score, it was us.

"But we have to kill these games off. It just shows that in football anything can happen.

"Obviously the way the goals went in was kind of freakish.

"But we have to be better and bigger than that - we have to stop teams getting to that point of being able to get lucky like that."