Lionel Messi missed Barcelona training on Thursday and will not travel to Bilbao for the champions' La Liga opener against Athletic Club at San Mames on Friday night.
It is the first time in ten years that Messi has missed Barcelona opening match of the campaign.
The Argentine attacker picked up a calf injury on his return to training with the Catalan club earlier this month and sat out the team's tour to the United States for the games against Napoli in Miami and Michigan last week.
Messi has been working alone as he steps up his fitness, as seen below in a video by @Otro on Instagram, but played no part in the session on Thursday evening and Barca boss Ernesto Valverde said he would be taking no risks with the five-time Ballon d'Or winner.
"We are not going to take risks with any player and less so with Leo," Valverde said in his pre-match press conference on Thursday. "He has still not trained with the team and he hasn't played.
"We will have to see how he is. Training alone is not the same as participating in a match. But his recovery is going well."
Antoine Griezmann will make his Barca debut on Friday and, with Messi out, the French forward should start alongside Luis Suarez and Ousmane Dembele in attack.
Frenkie de Jong is likely to feature in midfield after his summer move from Ajax, but Arturo Vidal and Arthur are not in the squad and goalkeeper Neto is injured.
Barcelona: Ter Stegen; Semedo, Pique, Lenglet, Alba; Busquets, De Jong, Rakitic; Dembele, Suarez, Griezmann
