The Australia cricket captain Michael Clarke suffered a lower back injury and was forced to retire hurt before tea on the opening day of the first Test against India in Adelaide.
The injury puts a question mark over his participation in the remaining three matches of the series as well as Clarke's ability to lead Australia into the 50-over World Cup early next year.
The 33-year-old was only playing after coming through a fitness test on a third hamstring strain in three months, problems which are related to his long-term degenerative back injury.
Clarke had made 60 not out when he twisted to avoid a short ball from Ishant Sharma.
Clarke had appeared in full control against India's bowlers and his retirement subdued the crowd of over 20,000.
He has missed just one of Australia's 40 Tests since he assumed the captaincy in 2011 but may come in for some flak for putting sentiment ahead of team interests by playing in Adelaide.
Clarke has spent much of the last two weeks leading the nation in mourning for his friend and former team-mate Phillip Hughes, who died after being struck on the back of the head by the ball in a domestic match.
Hughes's memory was being honoured throughout the match at the Adelaide Oval, where the lefthanded batsman played his state cricket for South Australia for the last couple of years.
Meanwhile the New South Wales fast bowler Sean Abbott has claimed two wickets in his first match since delivering the bouncer that caused Hughes' death in a freak accident.
The wickets came two weeks after the accidental blow suffered by Hughes at the same ground in NSW's Shield match against SA.
Abbott was warmly applauded by the crowd when he bowled his first over on Tuesday.
He delivered a bouncer with just his fifth ball.
The New South Wales players were wearing black armbands in memory of Hughes and have "PJH 707" stitched onto their shirts for the remainder of the season, a reference to the batsman being the 707th player to play for the state team.