Coetzee goes under the knife again
Coetzee made his Ulster debut in February, having joined the club in 2016. At the time of his signing with the Irish club, he was undergoing rehab on a long-term knee injury.
He will now undergo exploratory surgery to fully ascertain the extent of the injury after it was described as being a "significant" injury.
His performance lasted just a few minutes before he hobbled off the field, having twisted his left knee – the same as before.
This has thrown a cloud of doubt over his return to the international arena, after SA Rugby announced that only overseas-based Springboks with more than 30 Test caps will be eligible for national selection as of July 1.
The flank has 28 caps to his name and a lengthy spell on the sidelines could see his international career come to an end, should he opt to not return to South Africa to ply his trade.
There were further injuries to other Ulster players.
Tommy Bowe sustained a left ankle fracture in Ireland's Six Nations defeat at the hands of Wales on Friday night. He underwent surgery on Tuesday to stabilise the fracture and is expected to be sidelined for eight to 2 weeks.
Conor Joyce (right knee), Jonny Murphy (left shoulder) and Ross Kane (right thumb) sustained injuries in the Ulster A game against Munster A on Sunday afternoon. Andrew Trimble has had surgery for a left hand fracture sustained in the game against Treviso at the start of the month. He is expected return to action in approximately four weeks.
These players join Jonny Simpson (neck), Callum Patterson (ankle), Lorcan Dow (ankle), Louis Ludik (concussion), Kyle McCall (hamstring), Stuart McCloskey (calf), Johnny McPhillips (groin), Stephen Mulholland (shoulder) and Rob Lyttle (shoulder) on the current injury list.