By Toby Prince
The incident happened inside the opening stages at the Camp Nou, when Messi cut inside from the right wing, and his left footed shot was blocked by visiting defender Pablo Bigas.
He received treatment to his left knee on the pitch, then tried to continue for a few minutes, but soon admitted he could not continue and was replaced by youngster Munir El-Haddadi with just 10 minutes played.
After initial inspection in the dressing-room, the Argentine was quickly taken to the nearby Creu Blanca hospital for tests on the injured joint. After leaving the clinic on foot he was back at the Camp Nou by the final whistle.
Barca released a statement saying the injury was serious enough to rule Messi out of action for up to two months – making him a doubt for El Clasico against Real Madrid at the Bernabeu on November 21.
“Tests carried out on Leo Messi have confirmed that the player has suffered a tear in the internal collateral ligament of his left knee,” the statement said. “The time out will be approximately between seven and eight weeks.”
Messi will not feature in Tuesday’s Champions League group game at home to Bayer Leverkusen, or next Saturday’s La Liga trip to Sevilla.
Also on the horizon are Argentina’s World Cup qualifiers against Ecuador (October 8) and Paraguay (October 13), and a return to La Liga action on October 17 against Rayo Vallecano at the Camp Nou.