Both Matlaba and Van Heerden are suffering from Achilles tendon injuries while Nyauza had to pull out following his club’s hectic schedule in the CAF competition.
Pirates on Saturday beat AC Leopards of Congo Brazzaville 1-0 in a CAF Confederations Cup clash on Saturday and both Matlaba and Nyauza were part of the team that travelled to Congo.
Coach Ephraim ‘Shakes’ Mashaba and his technical team will draft in replacements for the three.
The squad will train this afternoon (Monday, 29 June) at University of Johannesburg Stadium, Auckland Park at 16h00.
Bafana Bafana assembled for camp on Sunday, 28 June in Johannesburg. They will face Mauritius on Sunday, 5 June at the Stade Anjalay in Mauritius.
Kickoff is at 15h00 local time (SA time 13h00).
South Africa won the first leg 3-0 at the Dobsonville Stadium on Saturday, 20 June.