The Argentine attacker has not yet recovered from the thigh injury he picked up against Atletico Madrid and will consequently miss the trip to Andalusia
The prolific attacker picked up a knock in Wednesday's Supercopa de Espana game versus Atletico Madrid and was taken off at half-time as a consequence.
Messi underwent further examination on Thursday, revealing bruising to his left thigh, and Martino has now revealed that he must skip the trip to Andalusia.
"We are pretty optimistic about Messi's recovery. He's not in the squad as a precaution, because we don't want to take any risks at this stage of the season," the Barca coach stated at a press conference.
The 26-year-old netted twice in Barcelona's 7-0 victory over Levante on the opening weekend of the new season, but won't be adding to his tally this weekend.
New signing Neymar is likely to make the starting XI for the first time in an official game on account of Messi's absence, with the Brazil international netting his first competitive goal for the club against Atletico in midweek.