Earlier this month, the Brazilian’s father revealed that Manchester United had made a €190 million (£144m) bid for the forward last summer, while reports claim that the club, along with Manchester City will try again at the end of the season.
Neymar’s current deal expires in 2018 but Barcelona are convinced the 24-year-old will extend his contract.
READ MORE | EXCLUSIVE: 'It's hard being Messi'
"Neymar will renew his contract," Vilarrubi told Club de la Mitjanit.
"It will be when he wants, and when the club wants. We are absolutely certain.
"He is committed to the team and is happy with his team-mates. The club gives him a lot of happiness."