Fast bowler Atkinson Adds to the English team's Fitness Concerns.
'Serious blow' for the touring side after Atkinson is forced off suffering a hamstring problem.
The pace bowler added to England's injury problems upon exiting the playing area on the second morning of the Boxing Day Test against Australia.
Atkinson pulled up with his left hamstring after the final ball that he bowled on Saturday.
The touring camp stated Atkinson had experienced "tightness" and would spend time off the field in order to be assessed "during the day".
The final Test of the tour at the SCG gets underway on Sunday, 4 January.
England have previously lost key quicks one seamer with a knee problem and Jofra Archer with an abdominal strain on this Ashes tour.
A replacement bowler was brought into the squad to provide backup.
His form was underwhelming during the first two matches, taking just three wickets.
He was left out of the third Test, only to be brought back for the Melbourne Test to fill the void.
Atkinson performed better in the fourth Test, claiming a couple of wickets during the host's first knock, then making 28 while batting being one of only three teammates to get into double digits.
Post a single over in Australia's second innings, he came back the next day and removed Scott Boland edging to the keeper.
However, towards the conclusion of that over, he bowled a change of pace to the batsman and promptly felt his left hamstring.
Gus Atkinson was brought back for the Boxing Day Test following his omission the previous Test.