NAPLES, Italy (Reuters) - Barcelona will be playing for their fans and not to silence their critics when they face Napoli in the Champions League last-16 on Wednesday, coach Xavi Hernandez said ahead of his side's return to the knockout stages after two years.

Xavi said he is not feeling the pressure in the face of criticism of his team, whose chances of defending their LaLiga crown have dimmed as they sit third on 54 points, eight behind leaders Real Madrid.

The former Barcelona captain, who said last month that he would step down at the end of the season after a run of poor results, feels the first-leg clash at Napoli is the ideal stage to show what they can do.

"There is excitement, hope and motivation to get through to the quarter-finals," Xavi said on Tuesday. "There is an ideal scenario for a good qualifying round and a great match."

"We are not playing to shut the critics' mouths, we are playing for our fans, for our prestige. We are in the round of 16, we haven't been here for two years, tomorrow is a great stage to enjoy and compete."

The Spaniard does not expect Monday's sacking of Napoli coach Walter Mazzarri and the appointment of interim boss Francesco Calzona to work in his side's favour and he anticipates a hard-fought tie against the Serie A champions, who are currently ninth in the table.

"They changed their coach a few hours before the match, they must have their reasons. It's not easy to prepare for a match that way, but the important thing is us," the 44-year-old said.

"We are talking about the reigning Italian champions, they have a great level. I don't think we are favourites, I see it as even.

"We are teams that have just won the league and it hasn't been our best season, if we are favourites, we have to show it on the pitch, here and in a few weeks at home," he added.

(Reporting by Janina Nuno Rios in Mexico City; Editing by Toby Davis)