The Argentina international has yet to put pen to paper on fresh terms with the Catalan giants, leading to suggestions that he may look to move on once his current deal expires in 2018.
Club president Josep Maria Bartomeu wants Messi's success at Barcelona to be rewarded with a mega-money contract, making him one of the highest-paid players on the planet, but La Liga rules restrict how much can be spent on wages.
"We're working hard to renew Messi," he is quoted as saying by FourFourTwo. "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 it would be stupid to let him escape.
"It's a matter that has to be analysed with a cool head and common sense. Barca cannot spend more than 70% 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."