The spearhead of Australia's attack trod on a stray cricket ball during the warm-up on the Edgbaston outfield as he caught a rugby ball and had to be helped into a groundsman's buggy after being helped in by his team-mates.

His place in the side was taken by fellow seamer Michael Kasprowicz.

McGrath, 35, who took nine wickets for 82 in the first Test win at Lord's, was carried off on a buggy and was later taken to a local hospital for X-rays.

"There's nothing obvious in the X-rays regarding bone abnormalities but we are awaiting further expert reports from a radiologist this (Thursday) afternoon," said Australia physiotherapist Errol Alcott.

McGrath, who suffered a grade two tear of his lateral ligaments, returned to the dressing room where his foot was elevated while the injury was being iced.

Australia captain Ricky Ponting, after winning the toss and electing to field, said: "I guess the good thing about it is that Kasper took five wickets in the tour game during the week (against Worcestershire) so he's in pretty good touch as well and I'm looking forward to seeing him bowl."

This was the second time in the last three Ashes Tests that McGrath had been out of action after missing the final match of the 2002-03 series in Sydney where England won by 225 runs.

At Lord's, where Australia won the first Test by 239 runs, McGrath -- a veteran of 110 Tests -- became the fourth bowler to take 500 Test wickets.

He joined teammate and leg-spinner Shane Warne, retired West Indies quick Courtney Walsh and Sri Lanka off-spinner Muttiah Murali-tharan as the only men to have reached the landmark.

Australia, winners of the last eight Ashes campaigns, are now 1-0 up in the five-Test series.