Australia is sweating on the fitness of Michael Clarke ahead of the first Test against India with the key batsman sitting out training on Tuesday with a stomach bug.

With the Australians lacking a frontline spinner and nursing allrounder Shane Watson through a chest virus last week, Clarke’s illness could not have come at a worse time just two days before the series opener.

Clarke’s ailment is thought to be less serious than the one seen off by a now fit Watson with a Cricket Australia spokesman saying the New South Welshman was not considered in doubt at this stage.

Much is expected of Clarke in this series, both as a middle order batsman and a dependable part-time spin bowler, his absence at training leaving captain Ricky Ponting to deputise as a net bowler with his modest off breaks.

Four years ago it was Clarke who stepped in for Ponting at Bangalore, winning his first Test cap after the skipper was ruled out of the first three matches of the series due to a broken finger.

Walking to the crease at 4-149 on the first day, Clarke made 151, an innings that remains his highest in Tests.