Seamer Gus Atkinson Adds to the English team's Fitness Worries.
'Significant concern' for the English camp after Atkinson is forced off with a hamstring injury.
The pace bowler further complicated England's injury problems when he left the field early on day two of the Boxing Day Test versus the Australians.
The pace bowler felt a problem in his left leg post-delivery in his spell during the morning session.
The England team stated the 27-year-old felt some "soreness" and was to take time off the field in order to be assessed "during the day".
The concluding match of the tour in Sydney gets underway this coming Sunday.
England have been without fast bowlers Mark Wood to a knee injury and Jofra Archer with an abdominal strain during this series.
Matthew Fisher was added to the party to provide backup.
Atkinson struggled in the opening two Tests, taking just a handful of scalps.
He was dropped for the Adelaide match, only to be brought back for the Boxing Day match as Archer's replacement.
Atkinson performed better in the fourth Test, claiming a couple of wickets in Australia's first innings, then making 28 as a batsman among just a trio of teammates to get into double digits.
Following a brief spell late on the first day, he came back on Saturday morning and had nightwatchman edging to the keeper.
Yet, towards the conclusion of that over, he bowled a slower ball to Travis Head and immediately felt for his hamstring.
The English bowler was brought back for the fourth Ashes Test after being left out the previous Test.