Warner replaces injured Shaun Marsh

Shaun Marsh has been ruled out of the second Test against South Africa and has been replaced in Australia's squad by David Warner. Marsh struggled with a back injury during Australia's humiliating loss in Cape Town, where he suffered the problem while running between the wickets during his first innings of 44.

Warner will join the tour on Monday ahead of the Johannesburg Test, which starts on Thursday, but Usman Khawaja, who is already with the squad, is the likely candidate to replace Marsh at No.3. Cricket Australia confirmed Marsh would fly home after he showed only slow improvement from his back problem.

The injury was so troubling for Marsh that on the second day in Cape Town he was at the team hotel and was not expected to take the field at all. But he refused to stay on the sidelines as Australia collapsed and he batted at No.10, although he was clearly hampered as he walked out to the crease.

"He was in considerable pain and was obviously restricted while batting in the second innings," Alex Kountouris, the team physio, said. He is slowly improving but will return to Australia for further investigation and treatment as he will not recover in time to play the second Test in Johannesburg."

The loss of Marsh is a significant one for Australia after their capitulation for 47 in the second innings at Newlands. Although he has played only three Tests, Marsh has been one of the team's most in-form batsmen, scoring a century on debut in Sri Lanka followed by 81 in his second Test and a pair of half-centuries in Australia's tour match in Potchefstroom.

His absence will be felt, with senior players including Ricky Ponting and Shane Watson struggling for form. Warner scored 148 in last week's Sheffield Shield match against South Australia and has been in irresistible form this year, but it would still take a brave selection panel to include him at the expense of one of the existing squad members.

"David has been in tremendous form for New South Wales in all forms of the game including a recent century for New South Wales in the Sheffield Shield competition," Andrew Hilditch, the outgoing chairman of selectors, said. "We are certain that should the opportunity present itself he will be ready to perform at Test level."

Australia were due to train at Newlands on Sunday but rain in Cape Town was complicating their plans. The squad flies to Johannesburg on Monday.