Geoff Cross became the second Scot forced to return home from a tour of South Africa because of injury, team officials confirmed on Monday.
The prop came on as a replacement in the 27-17 loss to Samoa in the first round of a four-nation tournament also featuring the Boks and Italy.
But a shoulder injury has ruled him out of the Test against South Africa this Saturday at Mbombela Stadium in north-eastern city Nelspruit, which will be staging Test rugby for the first time.
Hooker Pat MacArthur, whose Test debut lasted just five minutes against the Pacific islanders before hobbling off at Kings Park in Durban, withdrew from the tour Sunday with a knee injury.
Others battling against the clock to recover from injuries include flanker and captain Kelly Brown and officials said the planned Tuesday team announcement has been delayed.