Paceman Gus Atkinson Adds to the English team's Fitness Worries.
'Serious blow' for England as Atkinson is forced off due to a hamstring issue.
Gus Atkinson further complicated the fitness woes of the England squad upon exiting the field on the second morning of the Boxing Day Test against Australia.
The right-arm seamer felt a problem in his left hamstring post-delivery of the fourth over on Saturday.
Team management reported Atkinson reported "discomfort" and would spend time off the field to undergo evaluation "over the next few hours".
The concluding match of the tour at the SCG starts at the end of the week.
The visitors have previously lost strike bowlers Mark Wood due to knee trouble and another paceman to a side strain on the current trip.
Matthew Fisher was added to the party as cover for Wood.
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 Melbourne Test as Archer's replacement.
Surrey's Atkinson improved at the MCG, claiming a couple of wickets in Australia's first innings, before adding 28 as a batsman being one of only three English batsmen to get into double digits.
Following a brief spell at the end of day one, he returned the next day and removed Scott Boland taken by the wicketkeeper.
However, on the final ball of his spell, he sent down a variation to Travis Head and suddenly grabbed his left hamstring.
The English bowler was recalled for the fourth Ashes Test after being left out the previous Test.
