Only the Catalans have earned more points than the unbeaten Yellow Submarine, who are tied on 11 with champions Real Madrid and Atletico Madrid.
Barcelona, with a perfect record of five wins from five games, are four points ahead but face a difficult test at the Estadio de la Ceramica, a short journey down Spain's east coast.
Perez, part of the Spain squad which won Euro 2024, joined Villarreal in August from Real Betis.
After losing striker Alexander Sorloth to Atletico Madrid, the second-top scorer in Spain last season, Marcelino Garcia Toral's side put their faith in Perez and it is already paying dividends.
The 31-year-old striker netted a last-gasp winner against Real Mallorca last weekend and also struck the equaliser in a draw with Valencia and a later decider against Sevilla - three strikes putting him one behind the top scorer, Barcelona's Robert Lewandowski.
"I'm still adapting, learning better about the (coach's) ideas, and my teammates," said Perez.
"I'm seeing as I go what it is the team want from me - confidence rises with goals and I have to continue like this."
The striker said he feels happy and valued at Villarreal, an apparent dig at his former side.
"Everything happens for a reason, Villarreal came for me strongly, valuing me a lot as a footballer, giving me the importance I deserved," Perez told DAZN.
"I'm happy with the change, to be here, how things have turned out and the very strong start."
Villarreal also made other adroit moves in the transfer market, with Diego Conde, Sergi Cardona, Logan Costa and other arrivals making solid starts.
With Barcelona away at Monaco in the Champions League on Thursday, Villarreal can try to take advantage of the Catalans' potential fatigue.
Ayoze will be given support by playmaker Alex Baena and former Barcelona winger Ilias Akhomach, who moved to Villarreal last season.
"It is always difficult to face Barça, they are the leaders of La Liga, but we have clear ideas and we are working on them so that they come true in the match," said Akhomach, admitting it was a special match for him.
"I spent my entire childhood there and I have great memories - everything I took away from the club is positive," he continued.
Barcelona are without the suspended Ferran Torres, as well as various injured star names including Ronald Araujo and Frenkie de Jong.
Elsewhere Real Madrid host Espanyol on Saturday, while Atletico Madrid travel across the capital to face Rayo Vallecano on Sunday.
Player to watch: James Rodriguez
Rayo Vallecano's star signing, former Real Madrid playmaker James Rodriguez, could make an impact against Atletico Madrid on Sunday.
The Colombian international made his Rayo debut on Monday as a substitute and should get more minutes against the Rojiblancos.
The midfielder could be just what Rayo need to break through against Diego Simeone's Atletico who have had a strong domestic opening to the campaign.
Key stats
4 - Real Madrid have been awarded four spot-kicks, ahead of Alaves on two
7 - Barcelona's Lamine Yamal leads the league on goals and assists combined
45 - Alaves's Carlos Vicente has the most top flight crosses but no assists
