Alexis Sanchez has taken to social media to claim he is "sick", two days before he is scheduled to return to Arsenal training.
The forward is enjoying a break after leading Chile to the Confederations Cup final against Germany on July 2, and is expected to link up with the rest of the squad at London Colney on Sunday.
However, that is no longer certain following the player's post on Friday morning.
Sanchez, who has been the subject of ongoing transfer speculation this summer, has one year remaining on his Arsenal contract, but manager Arsene Wenger is adamant the club will not sell him.
Sky sources understand Paris Saint-Germain are prepared to pay more than £40m for the Chilean international, with wages in excess of £250,000 a week.
Wenger denied reports on Monday suggesting the 28-year old has asked to leave the Emirates, confirming he will be part of the team next season.
Despite Sanchez's illness, Wenger offered injury updates on the fitness of Gabriel, Jack Wilshere and Santi Cazorla.
"I would say that Gabriel is still a few weeks away because he has an inflammation of his bone," Wenger told the club's official website
He also confirmed Wilshere, who is recovering from a leg fracture following his loan spell at Bournemouth last season, is "close" to coming back to training.
However, the Arsenal boss is yet to set a definite date for Santi Cazorla's return to full fitness after he underwent multiple surgeries for an Achilles injury nine months ago.
"For Santi, it is difficult to set a definite date but he is getting better every day," Wenger added.