Seamer Atkinson Adds to the English team's Fitness Worries.
'Significant concern' for the English camp after Atkinson goes off with a hamstring injury.
Gus Atkinson further complicated the injury concerns plaguing England upon exiting the field on the second morning of the Boxing Day Test in the Ashes series.
Atkinson experienced discomfort in his left leg immediately following a delivery of the fourth over on Saturday.
Team management indicated Atkinson had experienced "tightness" and would spend time away from the action for further assessment "over the next few hours".
The series decider of the tour in Sydney gets underway this coming Sunday.
England have been without fast bowlers Mark Wood due to knee trouble and Jofra Archer with an abdominal strain on this Ashes tour.
A replacement bowler was called up to provide backup.
The seamer had a tough time during the first two matches, taking just a handful of scalps.
He was omitted from the previous Test, only to be brought back for the Melbourne Test as Archer's replacement.
The county bowler performed better in the fourth Test, taking two wickets during the host's first knock, and scoring 28 runs with the bat as one of just three English batsmen to get into double digits.
Following a brief spell at the end of day one, he resumed the next day and removed Scott Boland taken by the wicketkeeper.
However, at the end of his spell, he sent down a variation to Travis Head and promptly felt for his hamstring.
Gus Atkinson returned to the side for the fourth Ashes Test following his omission the previous Test.
