Record signing Edinson Cavani faces a race against time to be fit for the new season having only just started full training for the first time since joining Paris Saint-Germain.
Cavani joined the rest of his new teammates on Tuesday having previously undergone a specific individual programme.
It means the 26-year-old, known as the 'Matador', could yet be fit to face Montpellier on Friday night in the French champions' first game of the new Ligue 1 season.
The 64-million-euro ($85 million) signing was late back to pre-season training after taking part in June's Confederations Cup with Uruguay.
PSG coach Laurent Blanc said a decision will be made on the ex-Napoli striker's participation on Thursday.
"We're going to give ourselves another 24 hours to see if he'll be available to the group in Montpellier," Blanc said Wednesday.
"If he continues to progress as he is doing, (he could play) but he still needs more time to prepare because he started (training) later than the others and he also had a few worries concerning old injuries.
"It would be daft to make him play at all costs and ruin the detailed preparation that has been done with him."
PSG are also sweating over the fitness of Brazil-born Italy midfielder Thiago Motta, who sat out training Wednesday due to a calf problem.
The 30-year-old missed large swathes of last season due to a series of injuries, including to his calf.