Glenn McGrath hopes to be back in Ashes action for the fourth Test at Trent Bridge after he suffered a freak injury during a team warm-up on Thursday.
Australia's leading strike bowler, who took nine England wickets at Lord's, has a tear in his ankle ligaments.
"It takes a split second to do and I realised before I even hit the ground that I was out of this Test," he said.
"But I am confident that I can be right for Trent Bridge - at worst. I'll be back for the last two Tests at least."
Australia physio Errol Alcott was slightly more circumspect in his assessment.
"Glenn has suffered a grade two tear of his lateral ankle ligaments," he said.
"It is very early days. It is a bit early to say how long it is going to take.
"The rehab will be fairly intense in the first few days when you are trying to learn more about it and his reaction to the stress and the force that went through the ankle.
"It is important to get through that and then we will see if we are to treat things really aggressively or more conservatively.
"The X-rays don't show any bone problem but it is an ankle which has seen a lot of action for years. I'm not ruling anything out at the moment."
The Australian team had been practising with a rugby ball as an alternative to more traditional cricket routines an hour before the start of play.
But McGrath, 35, had to leave the Edgbaston outfield on a motorised buggy after stepping onto a stray cricket ball.
"I was out there with Brad Haddin just passing the football rugby-style.
"The ball skidded past me, I turned to run and pick it up and my first step planted on top of a cricket ball set out for fielding routines - and I went straight down," said McGrath.
"It was a sharp pain. I looked up and no-one was coming across to me. I don't think they realised what had happened."