Celtic manager Ange Postecoglou believes his side can only measure themselves against Bayer Leverkusen if they stick to their attacking principles in Germany.
The sides meet in the Europa League with Celtic knowing that a positive result will be crucial to their hopes of progressing into the knockout rounds of the competition.
Group leaders Bayer Leverkusen have lived up to their billing as top seeds so far and Postecoglou recognises that the game is among the biggest he has faced so far with Celtic.
He said: “I don’t think Betis away or Ferencvaros away were lesser challenges but the level of the opposition, the consequences of the result, being away from home, it’s going to be a good challenge.
“For us, what’s important is that we want to go there and not miss the opportunity to measure ourselves.
“We want to be playing at this level consistently. We want to be qualified for these tournaments and we want to reach knockout stages.”
Though their recent form has not been consistent, Leverkusen sit fourth in the Bundesliga and were 4-0 winners in Glasgow when the teams met in September.
“It will be a good challenge,” Postecoglou said. “They’re a good side.
“They’ve picked up their form in the league and are going well. We’ve played against them already so we know the quality of side we’re facing.
“To all intents and purposes, they are a Champions League team. It’s a super challenge for us away from home. There are also consequences on the result. When we played against them here, we did well in certain aspects but we also found that mistakes are going to get punished. That’s going to be the case in Germany.
“I’m sure we’ll have some bright spots, I still believe we can take the game to them, but there are going to be moments when our concentration is going to have to be at the highest possible level.”
The Celtic boss’ preference for an attacking style of football is well-documented and he insisted he won’t swap that for any attempt to stifle the game and try to squeeze a result from a defensive approach.
“I’ve always felt that the best way to measure yourself is to go out there and play your football,” he said. “You can go out there and kind of shy away from the contest and try and survive but I don’t think you’ll learn anything that way.
“We can go and be conservative, try and hold on, try and survive, but if we do that we’ll learn nothing.
“All you learn is that you’re inferior and you don’t believe you can be any better. The only way we’ll learn anything in this game is if we go out there and take the game to them. That may be a painful lesson for us all but ultimately it’s a better way for us to find out.
“It may not be a painful lesson, it may show that we’re making a hell of a lot of progress. I’d rather go there and find out about ourselves than just go there and try to survive. That’s not the way you develop or grow as a team. If we want to get to these levels, we’ve got to use these games as a measuring stick and the only way to get measured is to go out and put yourself out there.”