Francesco Acerbi insists Lazio need to be at their best on Thursday night because Celtic are "ruthless".
The Parkhead side battled back from a goal down two weeks ago to claim all three points as Neil Lennon's men sit top of their Europa League group going into the rematch in Rome.
Lazio are a different prospect at the Stadio Olimpico, but the Italian midfielder knows that they can't afford to take Celtic lightly as they have the quality to punish the Serie A outfit.
He said: "We played a great game in the away match, the coach said it too. If the little moments don’t go in your favour it's hard against teams like this.
"The mental approach is important, they’re fast and ruthless so quality isn’t enough. We’ll need to be focused, Celtic hurt you as soon as you make a mistake.
"We hope we can approach this game really well by limiting their opportunities and trying to score - as for how, I don’t know, you don’t know how you’ll win. But the approach, ruthlessness and fighting spirit are essential.
"If we don’t go on to the pitch knowing this is our last chance then it’s better not to go at all. That’s what we need tomorrow."
Acerbi, who will have the difficult task of containing Odsonne Edouard , says Lazio need to tighten things up at the back if they are to get the better of Celtic.
He added: "I’ve often played in a back-three. In Serie B and in Serie A. I enjoy playing that role and I do what the coach asks of me.
“In every game we try to defend together, we work on improving this aspect every day, trying not to concede goals. We’re also disappointed when we concede.
“We play every three days, and in that case you have to defend as a team. We know the movements, we study the opponents with tactics and with videos.
“Every game we try not to concede, but if we concede one and our forwards score two then it’s fine all the same. We try to win, that’s all that counts in the end.”
