Barcelona president Josep Maria Bartomeu has warned that there can be no let-up from the Catalans in the transfer market if they want to stay ahead of Real Madrid.
Luis Enrique led the Blaugrana to the treble last term by winning La Liga, the Copa del Rey and Champions League in a memorable first season for the coach.
Much of that success is owed to their devastating attacking triumvirate of Lionel Messi, Neymar and Luis Suarez, who netted 122 goals between them.
However, with Aleix Vidal their only incoming thus far, Bartomeu says that the club cannot afford to rest on their laurels as they look to preserve that dominance during the next campaign.
"We can't let up and by so doing hand our rivals, such as Real Madrid, the advantage. They are actively buying and selling players in the transfer market," he told a supporters group.
"The executive board should carry out functions that benefit the club.
They finished two points clear of their El Clasico rivals in La Liga last season.
