The star forward tore his left hamstring this week, which will rule him out for six to eight weeks.
Jordi Ardevol, Barcelona's former chief doctor, believes Messi's current injury has come about as a result of the thigh injury he sustained in the lead in to last season not being allowed to heal completely.
"After a player is injured, there is a period in which the head stays with the injury and that until the injury is completely recovered and the sensations are normal, you have to disengage the brain from the muscle somehow," Ardevol said.
"The thought has to be on playing and there is a period in which the player does not take it out of their head.
"During the holidays, after the injury late last season, I believe that Leo should have had a more specific plan.
"The feeling is that he was never entirely clear, there have been some intermittent periods of activity and mentally the counter was not put back to '0'."
Messi's current problem is his third leg injury this season.
