'Major setback' for England after Atkinson goes off suffering a hamstring problem.
The pace bowler increased the injury concerns plaguing England when he left the playing area early on day two of the Boxing Day Test against Australia.
Atkinson pulled up with his left leg after the final ball in his spell on Saturday.
Team management reported the 27-year-old had experienced "tightness" and would spend time off the field in order to be assessed "in the coming hours".
The concluding match of the tour at the SCG gets underway at the end of the week.
The visitors have previously lost fast bowlers Mark Wood to a knee injury and another paceman to a side strain on the current trip.
A replacement bowler was called up as injury reinforcement.
Atkinson struggled in the opening two Tests, claiming a mere three wickets.
He was dropped for the Adelaide match, only to be brought back for the fourth Test to fill the void.
Atkinson showed better form in Melbourne, taking two wickets in Australia's first innings, then making 28 while batting as one of just three English batsmen to reach double figures.
Post a single over in Australia's second innings, he came back the next day and removed Scott Boland edging to the keeper.
Unfortunately, towards the conclusion of the fifth over, he sent down a variation to the batsman and promptly felt his left hamstring.
Gus Atkinson was recalled for the Melbourne match after being left out of the third.