Barcelona must use common sense when it enters into negotiations with Messi, says club's chief executive.

Barcelona’s chief executive Oscar Grau says the Catalan club must adopt a ‘cool head’ when negotiating a new deal for Lionel Messi

Grau admitted that any improved contract for Messi will be determined by the club’s capacity to generate revenue from sponsorship deals and player sales.

Five-time Ballon d’Or winner Messi’s contract expires in 2018 and he is expected to seek financial parity with with the reported £21m a year earned by teammates Luis Suarez and Neymar.

But La Liga’s salary cap means Barca must exercise common sense, Grau stressed.

“We want the best players but perhaps we have to prioritise,” he added.

Barcelona’s Luis Suarez, Neymar and Lionel Messi celebrate a goal against Atletico Madrid during their Spanish First Division match at Camp Nou.

La Liga stipulates budgetary limits with each club at the start of every season, with club’s overall salary outlay limited to 70% of their budget on wages.

The big-money contracts awarded to Suarez and Neymar, limit the amount the club can spend on any one player, though Messi’s iconic status and commercial appeal outstrips those of his fellow forwards.

Messi, 29, reportedly earns about £19m and Grau admitted any increase had to be considered with a “cool head”.

“We have to make the numbers add up,” he added. “One option is to increase our revenues, as our economic strategy forecasts.

“The club wants the best player in the world to stay at Barca. I would like to ease the concerns of club members and supporters but we have to use common sense.”

Messi has spent his entire professional career with Barcelona, joining the club’s famed youth academy when he was 13 years-old. In sixteen years with the club he has broken many of Barcelona’s individual records, scoring 478 goals in 553 appearances and in the process becoming the all-time leading La Liga goalscorer with 319 goals.