“Celtic have to deal with the Dortmund atmosphere” – Lambert

Paul Lambert insists Celtic must “thrive” with the Borussia Dortmund crowd if they are to pull off a Champions League upset against last season's defeated finalists.

The former Scotland midfielder, who played for both clubs and won the Champions League with Dortmund, believes the game will test whether Celtic can “cope” with the highest level of European football.

Brendan Rodgers' side got off to a perfect start to their Champions League campaign with a 5-1 win over Slovan Bratislava last month, but face a far tougher test away from home at the German giants.

“Celtic are used to playing big games but you go up another level, no disrespect to the Scottish league but you are playing against a team that made it to the Champions League final,” Lambert told BBC Scotland .

“You have to deal with the atmosphere, you have to deal with the crowd, if you can't do that Dortmund will make it so difficult. You don’t want to have regrets, that’s important,” Lambert said.

“Last year and a few years before that, [Celtic’s] The level wasn't quite high enough for European football. The way the team started this year gives him a lot of confidence to come here and see where it takes him.

“You play a few levels higher and this is where you have to test yourself. Whether you can handle this level is the key, and if you can do that then you have a chance.”

“I’m curious to see if there’s a difference in performance. Don't take anything away from Celtic, they are a good team and play really well, but Dortmund are playing well in the league and have had a good result in Europe. “It's what makes a good game.