Hamstrung Johnson in doubt for Sydney Test

Mitchell Johnson's workload has started to tell - the Aussie spearhead in doubt for the Sydney Test with a hamstring injury.

Australian spearhead Mitchell Johnson in doubt for the Sydney Test with a hamstring injury. (AAP)

Australian spearhead Mitchell Johnson is in doubt for the fourth Test against India at the SCG, starting Tuesday, due to a hamstring injury.

Johnson didn't train with the Australians on Saturday and his condition will be further assessed in the lead-up to the fourth and final Test against India.

Johnson's heavy workload over the past two Tests is believed to have contributed to the problem.

If Johnson is unavailable for the SCG Test, Mitchell Starc looms as a probable replacement.

More to come