Possible replacements, Michael Kasprowicz and Paul Reiffel both suffered leg injuries during the Australian XI's victory against England in Hobart earlier this week.

However, Australian captain Mark Taylor was hopeful McGrath would be fit for the fourth Ashes Test. Taylor said McGrath complained of a virus on the final day of the third Test win in Adelaide that secured Australia the Ashes for a sixth consecutive time. ``He's had a week off and he's feeling a lot better,'' Taylor said.

Western Australia's Matthew Nicholson, 24, was a surprise replacement for Gillespie.

Taylor said he had only seen Nicholson bowl nine overs, for the Prime Minister's XI against England in a one-day match in Canberra last week.``I know from what I have heard and what I have seen he'squite sharp and can move the ball away from the righthanders,'' Taylor said.

``In that regard he's in the Gillespie mould but whether he's going to be as accurate and as consistent we may find out come Boxing Day.''

England will name their team after a Christmas Day fielding session. England's embattled cricketers will forsake the Christmas tree tomorrow to spend the morning as they have for most of the past two months: chasing leather.

England will be sweating through fielding training with temperatures forecast to reach 37 degrees celsius at MCG. More than 70,000 people are expected to follow tradition and crowd Australian cricket's oldest Test venue on Saturday.

Time, please: Television viewers and spectators at the Melbourne Cricket Ground will discover just how quick Australia's new pace weapon Matthew Nicholson is. A device called the speedster, which measures a cricket ball's speed every 1/1000th of a second, will be used during the fourth and fifth Ashes Tests and selected One-DayInternationals in the New Year.

The speed of each delivery will be shown on a giant digital display after each ball, with plenty of interest centered on Nicholson. There are suggestions he is Australia's fastest bowler.

Former Australian Jeff Thomson of the 1970s was timed at 160.4 km/h in 1975. His record has survived the test of time, with Pakistan's Shoaib Akhtar the next quickest on record at 148.8 km/h.