Arsenal were left sweating with a virus sweeping through their squad ahead of the lunch trip to Leicester.
Manager Mikel Arteta will leave it up to the last minute to name his team.
This is due to his medical team conducting tests on a number of players.
Both central defenders Ben White and Pablo Mari have been affected by this error in the past few days.
Now Arteta fears that others will be affected.
Mary was due to play in the Carabao Cup midweek win against Leeds, but fell ill on the eve of the match and withdrew.
White only lasted 55 minutes of Tuesday’s 2-0 win before he was forced out.
“We’ve had a little bit of sickness, abdominal pain and things like that but hopefully everyone is fine,” said Arteta.
“Ben hasn’t trained yet so we’ll have to wait and see how he feels before we make a decision.
“A few players weren’t able to train and we also had some blows in the match against Leeds. Hopefully we can get better news.”
Full-back Kieran Tierney missed Arsenal’s last two games with an ankle injury, while Granit Xhaka was out for the rest of the year after suffering knee ligament damage last month.
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