Steyn aggravated a right hamstring strain suffered during the recent Test series against Australia while playing a warm-up match in Fatullah on Tuesday, where he limped off after bowling 2.2 overs.

A statement from Cricket South Africa late Wednesday said Steyn will "continue to receive treatment from the physiotherapist to give him the best chance of recovery for the opening match".

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Du Plessis has a "50-50" chance of playing the opening match, the cricket board added.

"The medical team is cautious of rushing him too soon because of the explosive nature of T20 cricket and the back-to-back schedule of fixtures," the statement said.

"He will continue to receive extensive treatment and rehab to give him the best chance of regaining full fitness for the opening match."

If du Plessis sits out, one-day captain AB de Villiers is expected to lead the Proteas.

South Africa's second match is against New Zealand in Chittagong on Monday.

England and a first-round qualifier are the other teams in the group, with two advancing to the semi-finals.