Ange Postecoglou admits his Celtic side isn’t ready to challenge European football’s better clubs after a heartbreaking 3-2 Europa League away loss to German outfit Bayer Leverkusen.

On target to keep their hopes alive of advancing to the knockout stages when they led 2-1 deep into the contest, the Hoops conceded goals in the 82nd and 87th minutes to lose at Bay Arena.

With hopes of a top-two group finish gone, Celtic will now have to settle for Europa Conference League football in February following their final Europa League Group G clash against Spanish club Real Betis on December 10.

“It seems a long way away,” former Socceroos coach Postecoglou said.

My main thoughts are around how do we get to this level?

“This is where we want to be. It’s not that we are disappointed we are in the Conference League, but we want to be competing at this level with these teams.

“I felt with all the group games we slowly became a better side at dealing with the best teams in this competition.

“How do we bridge that gap? I want us playing against the best in the best competitions.

“There is still a little gap there and we have to still build from that. The Conference will maybe give us an opportunity to play in different conditions against good teams.

There is a lot at stake in European football. Can we still hold up and stand up against the best? That’s what’s important to me.

“We came here to test ourselves, to find out where we are at, and I think we did.

“We know we’re not at this level yet, but we came here and we were determined to take it to a good opponent and I thought we did that.”

Celtic trailed 1-0 early before a penalty from Josip Juranovic and a goal from Jota gave them a 2- l lead in the 56th minute.

“We gave ourselves a chance of pulling off a great result, but ultimately we couldn’t handle it at the end and they obviously got the two late goals,” Postecoglou said.

“It’s disappointing, definitely, disappointing for my players, but at the same time it’s a great learning tool for us in our development.

“We know there’s a gap between us and the best, but we will bridge that gap if we keep taking this approach whenever we play these teams.”

Socceroos playmaker Tom Rogic took no part in the match, with Postecoglou opting to give him more time to recover from a hamstring injury.

Celtic returns to Scottish Premiership action on Monday morning when they host Aberdeen at Parkhead.