Barcelona CEO Oscar Grau has called for patience as the club continue to work on a new deal for Lionel Messi.
Messi is into the last 18 months of his contract and some reports in Spain claimed at the end of last year that he was considering his future.
But Grau, speaking in Barcelona on Wednesday, was more cautious and said: "We're working hard to renew Messi.
"We're keen to get it done and I am sure we will find the formula. By saying this I want to reassure supporters, because when you have the best [in the world] it would be stupid to let him escape."
With wages in football soaring, Bartomeu's promise to make Messi the sport's top earner means negotiations may not be straightforward.
Luis Suarez and Neymar both signed improved contracts in 2016, and Grau stressed: "It's a matter that has to be analysed with a cool head and common sense.
"Barca cannot spend more than 70 percent of the budget on salaries, therefore we have make sure things balance.
"One option is to increase revenue, as we hope to with our strategic plan [to bring in €1billion annually by 2021].
"We want to have the best, but we must always prioritise. The objective is for the best player in the world to stay at Barcelona and it's the same with everyone, although especially with those that were formed in La Masia, who I think should retire here."
Grau was also asked about the possibility of the club getting involved in the January transfer window.
Darijo Srna is one of several right-backs to be linked with taking the place of the out-of-favour Aleix Vidal, but there will be no signings unless players depart first.
"It's a matter we want to work on with discretion, while keeping our budget in mind," Grau said.
"If there are no outgoings, though, there will be no incomings. If an opportunity comes up, we will look into it."