England pace spearhead Steve Harmison is in doubt for next week's Ashes opener with a side strain that forced him out of the tourists' final lead-up match here Friday.
Harmison, who has taken 179 wickets in 45 Tests, was left out of the three-day tour practice match against South Australia at Adelaide Oval as a precaution.
England team management sent Harmison for scans, which were inconclusive, and he had a painkilling injection.
Coach Duncan Fletcher said there were doubts over whether Harmison would play in the series opener, which starts in Brisbane on next Thursday.
"He's not guaranteed for Brisbane with that problem he's had before," Fletcher told after the opening day of the three-day game against South Australia.
"So we'll just have too see how this injection goes and what effect it has on him.
"We're not going to guarantee it, but we're planning, if he's fine tomorrow and it's not as bad as it was, we'll give him a ball and see how he feels with it."
How Harmison bowls in the nets Saturday could determine whether England begin the Ashes campaign with the man, who rattled Australia's batsmen on the first day of the 2005 series and claimed 5-43.
With Simon Jones injured and captain Andrew Flintoff still regaining bowling fitness after ankle surgery, England desperately hope the Durham speedster can play a major part in the series.
"He had an effect in the Ashes last year. He's been an effective bowler for us and the other bowlers feed off him," Fletcher said.
"We've just got to monitor the amount of balls he bowls because we've got to get some mileage in his legs."
An England team spokesman said Harmison felt tightness in his side when he woke on Friday and although he bowled during the warm-up, team management decided to leave him out of the Adelaide game.
The news comes three days after the senior opening batsman Marcus Trescothick quit the Ashes tour and returned home citing a recurrence of a stress-related illness.
Lancashire paceman Sajid Mahmood, thought to be out of the running for Test selection after missing the previous three-day game against New South Wales (NSW), replaced Harmison in the match against South Australia.
Harmison's withdrawal leaves him underdone for bowling in the lead-up to the Ashes, as he struggled through the Champions Trophy tournament in India and bowled only 25 overs against NSW.
Harmison also sat out the first match of the Australian tour, the Prime Minister's XI game in Canberra on last Friday.
He struggled with a side strain during England's Test series against Pakistan in August and missed the following one-day series.