England are confident they have the resources in their squad to go on and win the Ashes even if Andrew Flintoff joins Kevin Pietersen on the casualty list for the remainder of the series.
Having suffered the major blow after the second Test at Lord's of losing star batsman Pietersen, who has been ruled out of the remainder of the npower series following an Achilles operation, England were relieved all-rounder Flintoff was able to play his part in the drawn third Test at Edgbaston.
But for the second successive Test Flintoff finished the match clearly struggling with his troublesome right knee and now faces a race against time to prove his fitness before the fourth Test begins at Headingley on Friday.
The 31-year-old all-rounder has had injections to get him through the last two matches, but England captain Andrew Strauss believes there is the manpower available to maintain their series lead even if Edgbaston does prove to be Flintoff's swansong before his Test retirement.
Asked whether England could win the series without Flintoff, Strauss replied: "Yes, I think we can - we've had to plenty of times over the last two years so it wouldn't be anything new to us.
"Generally the bowlers have stepped up when he hasn't played but at the moment he's in great nick with both ball and bat so we don't want to play without him if we can help it.
"We will have to swing with the punches we get and if that is the case then I think we've got a good enough squad to be able to deal with that.
"He's got to be honest about his body and he has been so far. He's obviously desperate to play in these last two games but I think he realises that if he's not fit then he won't help us."
Even without Pietersen, England were still able to claim a 113-run first-innings lead in Birmingham but, despite their best efforts on the final day, Australia battled to a draw with Michael Clarke claiming his 12th century on his 50th Test appearance.
Flintoff bowled only 11 overs during the day and none at all in the final session, but Strauss denied he was attempting to manage his injury to ensure his involvement at Headingley.
"I suppose at the back of my mind I'm conscious that, when the conditions aren't really helping him, there's no point in tearing him to death and that's the reason he didn't bowl in the final session," explained Strauss.
"We're still very optimistic he'll be okay for Headingley. There is obviously some soreness there. I don't think there's anything that's deteriorated massively over the course of the game, but he needs to rest up well because back-to-back Tests are hard for any bowlers and we'll see how he is on Thursday."
England are due to announce their squad for Headingley this afternoon and may also have to check on the fitness of Durham seamer Steve Harmison, who has been included in the last two Tests without making the starting line-up.
Harmison suffered blistered feet during Durham's championship victory over Sussex at Chester-le-Street but coach Geoff Cook believes he will be fit enough to feature at Headingley if required.