The Bianconeri's place in the Champions League knockout stages is already clinched heading into matchday six, with Sarri's team guaranteed top spot in Group D.

Juve has won four and drawn one in Europe so far, continuing Sarri's impressive personal run in continental competition after he led Chelsea to Europa League success last season.

But his side are second in Serie A and lost for the first time this season against Lazio at the weekend, meaning Sarri sees room for improvement even in a fixture they need not win.

"We know that we have to work to do better, but we are calm," said Sarri. 

"We need a spark, but that can be many things. We've got to move the ball quickly and not defend too deep after we've taken the lead. It's important that we always try to control the game.

"These are all things that represent a change of mentality at Juventus, so they do not come automatically. We've seen them in moments, for example the first half in Rome [against Lazio]."

Sarri wants his side to demonstrate a strong mentality in their performance, even with their passage already secured as Leverkusen still hope to overhaul Atletico Madrid for second spot. 

"The first time I was contacted by the Juventus hierarchy, I asked how come they only managed three points in the final Serie A games of the season," he said. 

"I said it would be a bad sign of their mentality if they justified it with the fact the Scudetto had already been won.

"We have the privilege and the honour of playing in the Champions League. I expect a strong and focused performance, because there are always objectives. I ask for a performance, then the result can come or not."