Munster have confirmed that a member of their squad in South Africa has tested positive for Covid-19.
The province's squad will remain in Cape Town where they moved from Pretoria on Saturday as they await guidance from health authorities.
The squad and backroom team will now isolate in their hotel in South Africa while they wait for further instruction.
They had hoped to return to Ireland on Sunday but those plans have been shelved due to the positive case.
"Munster Rugby will remain in Cape Town while we wait on next steps from the health authorities after returning one positive case in our latest testing," the club wrote in a statement.
"In taking all precautions and prioritising the health and wellbeing of everyone Munster Rugby will not travel today and will return to their hotel for an isolation period as a matter of priority."
Meanwhile, Cardiff said they have been unable to depart following two positive cases, one of which is suspected to be the new variant Omicron.
The Welsh club said in a statement: “As a consequence of one of these results suspected of being Omicron, the entire travelling party have returned to their hotel to isolate.
“Cardiff Rugby continue to work with the South African Rugby Union, the Welsh Rugby Union and public health authorities both at home and abroad to decide the next course of action.
“The club are also continuing to work with all relevant authorities to secure the travelling party’s return to Wales when safe and appropriate.”