Walter Mazzarri's side were considered to be one of biggest threats to Juventus' bid to claim back-to-back Scudetti, but the Partenopei have had a slump in form - with only one win in their last four league encounters.
Yet Lavezzi, who has remained in contact with his former team-mates, still has faith that they can mount a serious challenge for the league title.
"Napoli are doing very well this season," he was quoted by Calcio News 24.
"I saw the [1-1] draw with Torino, and they were unlucky to concede a goal when the game was almost over.
"I speak to them often and they sound happy with their performances. I think they will fight for the title."The Argentine attacker spent five seasons with the Azzurri before moving to the French capital outfit in the summer.