The four-time world player of the year is facing six to eight weeks on the sidelines with a hamstring injury, the third such setback this season.
Argentine doctor Luis Garcia, who is not an employee of the Spanish champions, has been assigned to work with the 26-year-old on his recovery prompting speculation Messi was unhappy with the club's own medical staff, and in particular physiotherapist Juanjo Brau, over his recurring injury.
But Barca sporting director Andoni Zubizarreta denied any unrest claiming Garcia is 'very well known to our medical staff'.
And Messi's management team backed up his claim insisting they had no problem dealing with Garcia, a man they had worked closely with in the past.
In a statement Leo Messi Management said: "The process of recovery from the injury suffered last Sunday began on Monday. This injury, although of the same type and to the same leg, is not related to any previous ones.
"Being a player of the Asociacion de Futbol Argentino (AFA), and having games programmed with the national team, the licensed kinesiologist Dr Luis Garcia arrived yesterday in Barcelona to represent the national team, to monitor the injury, and to know the state and scope of the same.
"Barca's medical services, as always, are those who take charge of accompanying him and treating him, like any other player at the club in other occasions.
"So they will be supervising his injury during the whole process, including when Leo travels to Argentina during the Christmas period.
"We want to deny completely the information published in some media, and confirm the comments of different club figures.
"Juanjo Brau, a great professional who has been close to Messi for a long period of time in recent years, no longer works day-to-day with Leo because FC Barcelona promoted him professionally.
"His current responsibilities are coordinating the club's first team squad physios.
There have been no professional or personal differences, nor a distancing outside of not being as close during their daily work."