Later on Wednesday, the Lions announced two players were isolating after one of the management team tested positive.
The Lions' warm-up fixture against the Bulls on Saturday was postponed because of Covid-19 cases in the hosts' camp.
South Africa is currently battling a third wave of infections.
The Springboks have had to isolate twice in the past two weeks, with their three-Test series against the Lions taking place on consecutive weekends from 24 July.