The 26-year-old only penned a new five-year-deal with the La Liga champions back in February, but reports in Spain have suggested that summer-signing Neymar has since overtaken him as Barca's biggest earner.
Javier Faus, Barcelona's vice-president, had questioned whether Messi deserved a new deal earlier this month, although the Argentina star maintains that he never asked for one.
"Mr. Faus knows nothing about football and wants to run Barcelona like a business, which it's not," Messi told Catalan radio station Rac1.
"Barcelona is the best club in the world and it should be run by the best directors in the world.
"Neither I nor any of my representatives have asked for an improved contract.
"The truth is that I'm focused on my recovery and not thinking about anything else."
Barcelona have announced that Messi has been given the green light to begin the third phase of his recovery programme from a hamstring injury.
The Argentina international is in Buenos Aires as he continues his rehabilitation from the injury he sustained against Real Betis on November 10 and will keep him sidelined until the new year.
Messi underwent further tests at the Argentina Football Association's (AFA) facility on Friday where it was confirmed the 26-year-old can move on to the next stage of his recovery.
Barca announced on their official website: "On Wednesday it was confirmed that Leo Messi's recovery was on track, and this Friday additional tests at AFA facilities confirmed that the Argentinian player has progressed past the clinical stage of his recovery.
"The player is now focused on the third stage of his recovery, which focuses on physical conditioning."
The injury is set to keep Messi out for between six and eight weeks in total, meaning he is in line for a January return.