Australia all-rounder Shane Watson was rushed to hospital in Chandigarh on Tuesday with chest and stomach pains.
Watson took 3-16 against England on Saturday
Tests showed he was suffering from gastritis, which commonly causes heart-burn and chest pain.
But Australia coach John Buchanan is optimistic Watson will be fit for Sunday's crucial Champions Trophy match against India in nearby Mohali.
"The hospital has diagnosed gastritis, so that should pass within 24 or 48 hours," said Buchanan.
Several of the Australian squad have missed training after coming down with stomach complaints.
"We've had a couple of bouts of sickness already," Buchanan said. "We're taking every possible precaution but sometimes those things happen."