They could yet still win the group, but have to overturn the 2-0 home defeat to Barcelona.
“It won't be easy to score the three goals against Barcelona to take the top spot, but we'll try our best," Bonucci told Sky Sport Italia.
“We know there's a process and a journey we need to go through. The target was to qualify for the Round of 16 and be in the running with Barcelona for the top spot until the end, so we've achieved that. Now we'll try to complete the job."
Bonucci added: “I think we are on track considering we didn't have any real rest or the kind of pre-season training routine you need when there are many changes both on the bench and in the squad.
“I see from everyone the desire to improve and grow. If we look at all the big clubs around Europe right now, they are all struggling in a way."