The Argentine had missed Barca's win over Malaga at the weekend due to a thigh knock but practised normally ahead of their clash with Atletico Madrid on Wednesday
The Argentina international was withdraw at half-time of the two-legged Supercopa clash against Diego Simeone's side last week and was forced to sit out the weekend's 1-0 win over Malaga.
However, he has now been passed fit to face the capital club at Camp Nou and practised with his team-mates ahead of the clash.
"Leo Messi was back in training with the rest of the squad this lunchtime after being rested as a precautionary measure for the game against Malaga, following the bruised thigh he suffered against Atletico Madrid last Wednesday," a club statement read.
Meanwhile, those who were involved in the narrow win at La Rosaleda did recovery work, having stayed overnight in Malaga.