Adelaide, Dec 13 (IANS): Michael Clarke's injury woes have continued, with the Australia skipper being sent for scans on his right hamstring after limping off the Adelaide Oval Saturday midway through day five of the first Test against India.

Clarke pulled up sore after he sprinted and bent down to stop a ball in the field, clutching at the problem area.

Team physio Alex Kountouris rushed onto the field as Clarke lay on the ground, before the skipper slowly limped off the playing arena with Kountouris by his side.

Clarke posted a courageous hundred during the first innings of the match despite being forced to retire hurt on 60 midway through the opening day with a back injury.

Speaking before day two, Kountouris said Clarke's lower right back injury was "probably" unrelated to the left hamstring injury he suffered during a one-day match against South Africa last month.

That injury, the third time he's hurt his left hamstring this year, had put Clarke in doubt for this Test, but he was cleared to play by medical staff Monday.

At this early stage, it's unclear whether or not the Clarke's right lower-back injury is related to this latest injury to his right hamstring.

The early stages of day five initially hinted at a slight improvement in Clarke's condition, after he took up his regular position at first slip to the spin of Steve Smith just before lunch.

The 33-year-old has managed chronic back problems for most of his career and the repeated hamstring injuries are sometimes related to his troublesome back, and this latest setback will cast further doubt as to his availability for the second Test in Brisbane, beginning Wednesday, Dec 17.