Leinster captain Isa Nacewa and fellow New Zealander Jamison Gibson-Park have been denied entry to South Africa because of visa problems.
It is understood the pair did not have the visa New Zealanders require to enter the country when the squad arrived in Johannesburg.
The Irish province face Southern Kings on Saturday and then play fellow Pro14 newcomers the Cheetahs on 22 September.
A statement released by Leinster said that the process was “ongoing”.
“Leinster Rugby can confirm that two members of the touring squad to South Africa, Isa Nacewa and Jamison Gibson-Park, encountered visa issues this morning upon arrival in Johannesburg. As this process is still ongoing, Leinster Rugby will be making no further statement,” the release read.
Nacewa and Gibson-Park were refused entry on their arrival by customs at Tambo International Airport.
South African law changed at the beginning of the year to require citizens from New Zealand to have a visa, where previously none had been needed.
The encounter with the Southern Kings on Saturday afternoon will be played at the Nelson Mandela Bay Stadium in Port Elizabeth, while the match with the Cheetahs will take place in Bloemfontein.