Juve go into the second-leg of the round 16 tie trailing 2-1 on aggregate.
Bonucci said, “We'll take to the pitch with the Juventus' spirit with humility and respect. We are aware that we can get achieve great results with sacrifice.
“We must be focused and not rush to score immediately. We need a goal and we can score it also at the end of the game. We are aware Porto are not going to defend only.
“We can't afford to throw anything away tomorrow. It's hard to have the right approach when you play one game every three days, but it's no excuse.
“Cristiano is always ready to play these games. Some time ago, he said he would play only Champions League games. So, you can imagine his energy for tomorrow's game."