The Argentina international was substituted at half-time in his side's Supercopa de Espana first-leg draw with Atletico Madrid on Wednesday after feeling pain in the back of his thigh. 

And Barcelona have now confirmed the 26-year-old has "bruised the femoral biceps tendon in his left thigh", meaning he could be unavailable for their second league game of the season at La Rosaleda. 

In a statement, the Camp Nou outfit said: "The FCB Medical Services have announced that they will be monitoring the player’s progress this week before deciding whether he will be fit to play on Sunday."

Manager Gerardo Martino had said after the Atletico match that Messi - who scored twice in Barcelona's opening La Liga fixture of the season against Levante last week - was unable to move freely, leading to the decision being made to withdraw him. 

The second leg of the Supercopa tie takes places at the Camp Nou on Wednesday after the first game ended 1-1.