England will be forced to make a change for the first time in the series after pace bowler Simon Jones lost his fitness battle and was ruled out of tomorrow's Ashes decider.
The Welshman misses the fifth Test at The Oval, where only victory for Australia will deny England a first win in nine attempts in cricket's oldest contest, having taken 18 wickets in four appearances.
The 26-year-old was hopeful of overcoming the ankle injury which impaired him in the tense win over Australia at Trent Bridge, which put Michael Vaughan's men 2-1 ahead in the series, but suffered discomfort when running yesterday morning.
He will rest for a fortnight in the hope that the bone spur eases sufficiently to avoid surgery, the course Andrew Flintoff took following a similar problem last winter and an outcome which would almost certainly rule him out of the tour of Pakistan.
"There was no chance. It is a sickening blow," said Jones, after his light jog at Lord's. "I have had a few injuries in my career, you have to get over the disappointment. These things happen.
"I'm going to go home and chill a little bit and then I will come back to be with the boys and support them."
Jones has managed only 18 Test appearances in three years, with almost half that period spent recovering from the knee ligament injury incurred in Brisbane at the start of the 2002-03 Ashes.
Since then, the Glamorgan paceman has become an integral part of England's pace quartet and his displays in Manchester and Nottingham have arguably been his best in the international arena.
England's management hope rest will be the best cure to ensure Jones' ability to reverse swing the ball will be available in the three-Test series in Pakistan.
The England and Wales Cricket Board's chief medical officer Dr Peter Gregory said: "Surgery is an option but the advice we have received from two leading specialists in the field is that the injury may still settle without recourse to an operation."
Vice-captain Marcus Trescothick says the absence of Jones, whose victims have come at 21 runs apiece, will be significant, suggesting he is at the peak of his powers.
"It's a little bit sad," Trescothick said. "Simon has been a great performer so far in this series - the two five-fors he took have been really important to making waves and bowling them out.
"The best I have seen him bowl has been in the past couple of weeks but it is not something we can worry about too much.
"To lose a major player in your team, who has done so well, is obviously disappointing but it gives someone else an opportunity to come in and play in a series like this."
Either all-rounder Paul Collingwood or James Anderson, the Lancashire fast bowler, will come in for Jones, with the decision unlikely to come until tomorrow morning.
"The guys are bubbling with the air of the whole thing, it is an exciting time for us," Trescothick added. "Every moment of every day so far has been very tense: it has been like three days in one, it has been that full on.
"It is exciting, great things lie ahead if we were to win this game. We can't get drawn into what is going to happen, we have to focus on what we have to do in this game. If we do get carried away I fear what would happen.
"The reason why we are in this position is because we have played in a certain fashion. It is important to keep doing that otherwise we will get drawn into a negative mindset."
Shane Warne, meanwhile, is bracing himself for his final Test on English soil saying the pressure is on Australia like never before. Since dismissing Mike Gatting with the "wonder-ball" at Old Trafford in 1993, Warne has taken 117 wickets in 21 Ashes Tests in this country. In that period he has experienced only five defeats in this country.
Warne said: "I thought the pressure was on England in the last Test match because they knew all we had to do was win one of the last two and if we won that last Test it was all over - the pressure is on us this time as far as I'm concerned.
"We have to play well for five days and if we don't play well we'll lose the Ashes for the first time in 20 years, hopefully that will make us respond and the guys will soak it up and see it as a challenge rather rather than fear it. There is a calmness in the group and the guys are looking forward to it."