The Netherlands international left Anfield at the end of his contract, following five seasons as a key cog in Jurgen Klopp's side.
Wijnaldum was announced as a Paris Saint-Germain player earlier this week after agreeing to a bumper three-year contract with the Ligue 1 giants.
“Unsung hero. People talk about all the great players Liverpool have and he very rarely gets a mention," Neville told ITV Sport.
“I think he'll be badly missed next season, very difficult to replace him at Liverpool.
“He's one of those players that keeps things ticking. You don't look at him and think he's doing anything outstandingly well, but I would imagine his teammates respect him enormously because he covers a lot of areas on the pitch.
“He does things simply for his teammates, he's an unselfish player and he's an important player for this Dutch team."