Madrid, Aug 14 (IANS): FC Barcelona kick off the post-Messi era in the Camp Nou Stadium when they entertain Real Sociedad on Sunday night in what promises to be a good test of the capacity of Ronald Koeman's side to battle for the title without the Argentinean.

Speaking earlier in the week, Koeman stressed the importance of other players stepping up to score the 30 league goals Messi netted last season, but with new arrival Sergio Aguero out until November with a calf injury, there are still doubts over whether other new arrivals, Eric Garcia and Memphis Depay will be able to play.

The problem for Barca is that their wage bill is still too high for the duo to be included in their squad and they need to either offload players -- Samuel Umtiti and Miralem Pjanic - or get others to lower their wage ceiling enough to inscribe the new arrivals in their squad.

The uncertainty is a big handicap for Koeman, who has Ousmane Dembele, Ansu Fati and Marc Andre Ter Stegen still recovering from long-term injuries, while Clement Lenglet and Oscar Mingueza are also out and Frenkie de Jong is doubtful, reports Xinhua.

All of that means that 18-year-old Pedri will almost certainly start just 10 days after finishing playing in the Olympic Games, effectively moving from the end of last season to the start of the new campaign without a break.

18-year-old Yusuf Demir, who has impressed after joining Barca's B-team squad on loan from Rapid Vienna, could also find himself in the squad and Koeman will have to use the B-team to make up the numbers on the bench as he did in their recent Joan Gamper trophy win over Juventus.

Real Sociedad also have four players back after Olympic duty with Mikel Oyarzabal (who like Pedri was also in the European Championships), Mikel Merino, Martin Zubimendi and Modibo Sagnan all likely to travel after representing Spain and France in Tokyo.

One big doubt is striker Alexander Isak, with last season's top scorer struggling with a muscle injury, with Willian Jose likely to deputise.

There will be 20,000 fans back in the Camp Nou for the game, but while most clubs can expect their fans to get behind them, after the difficult events of recent days, Barca president, Joan Laporta must wonder about the reception he and his directors will receive.