The back row hurt his ankle and suffered a blow to the head during the Springboks' warm-up win over Argentina in Pretoria.

Coetzee is expected to be sidelined for 12 weeks.

Lizo Gqoboka, Marvin Orie, Thomas du Toit and André Esterhuizen have also been released by South Africa.

Coetzee was recalled to the Springboks training squad for Japan after an impressive season for Ulster, which saw him named Ulster Rugby Writers' Player of the Year.

He had endured an injury-hit spell after moving to the province in 2016, putting his Springbok career on hold.

The injury will rule him out of the start of the 2019-20 season for Dan McFarland's side, who begin their Pro14 campaign at home to Ospreys on 27 September.