Carlo Ancelotti was looking forward to meeting up again with his old friend Gianluigi Buffon on Monday ahead of Tuesday's Champions League clash with 'unpredictable' former club Paris Saint-Germain.

"It's always a pleasure to meet him again, to see that he is motivated despite his age, I have great respect for the professional and great affection for my friend," said Ancelotti.

Buffon, 40, will make his European debut with the French champions against the heated backdrop of 55,000 fans in the San Paolo Stadium in his first game in Italy since leaving Juventus in the summer.

"Even if the result in the first leg (2-2) could have been better for us in the end we will need something extraordinary to beat Paris," said Ancelotti, who coached PSG from 2011 to 2013.

Napoli are second in Group C on five points after three games, one behind leaders Liverpool.

PSG face the prospect of potential early elimination as they sit third with four.

"The group remains very balanced and uncertain, which is a very positive thing for us," estimated Ancelotti.

Napoli are counting on Ancelotti's European credentials -- the veteran coach won the Champions League twice with AC Milan in 2003 and 2007 and once with Real Madrid in 2014 -- to pull them through against PSG, who have the two most expensive players in history in Neymar and Kylian Mbappe.

"We know the difficulties, the importance and what we have to do tomorrow night," said Ancelotti.

"They remain a strong team, very difficult to deal with, and at the moment they're totally unpredictable.

"Having done well in the first leg gives us more conviction, but it's still a really difficult game."

Meanwhile, Ancelotti added that Qatar-owned PSG were not the same team he coached to the Ligue 1 title in 2013.

"There are many differences, the team was under construction, but now the project has reached the final stage."