Arsenal reportedly fear that talismanic forward Alexis Sanchez could go on strike and refuse to train with the squad ahead of his expected return on Sunday.
The Chilean international was afforded additional time off after his participation in the Confederations Cup earlier this summer, while Arsenal confirmed this week that he was to be expected back on Sunday while his teammates feature in the Emirates Cup.
That was clouded with doubt after he posted an image of himself on Instagram declaring that he was ill with a flu, and that immediately raised alarm bells as to whether or not it was genuine or a move to avoid heading back to training with the Gunners.
According to The Sun, the £50m-rated star has already rejected a £275,000-a-week contract offer from Arsenal as he has his heart set on a move to either Manchester City or Paris Saint-Germain, and that has led to their suggestion that he could go on strike to force the switch.
With just 12 months remaining on his contract and with no suggestion that a renewal will be signed, the north London giants will have to make a decision on whether to keep him or sell him now to ensure they receive a significant fee.
It remains unclear to all concerned as to whether or not Sanchez will be back in training on Sunday, but ultimately that will give a clear indication as to whether or not he intends on sticking around, unless the club confirm the illness and additional time off.