South Africa have confirmed Bongi Mbonambi, Scarra Ntubeni and Dan du Preez have been cleared to link up with the squad after completing their mandatory self-isolation period following positive COVID-19 tests results.

The trio were forced to sit out South Africa A's victory over the British and Irish Lions on Wednesday, as well as the shock 17-14 defeat to the Bulls at Cape Town Stadium.

With six days to go until the series opener against the Lions in Cape Town, all three players have been cleared to resume training with their team-mates.

South Africa had not played a Test match in 20 months prior to beating Georgia two weeks ago, and Kwagga Smith accepts there is a lot of work ahead for the reigning world champions.

"We haven't played Test matches in almost two years, so we got together and started working on it in the last three games and we can now analyse that," he told SA Rugby's official website.

"We need to use our opportunities because in Test matches there aren't many of them, so we have to convert them into points, and we have to sharpen up and get into our system and enforce it onto them."

The majority of the Boks' fringe players failed to impress in the defeat to Bulls, whereas the Lions flexed their muscles with a 49-3 win over the Stormers in their final warm-up match.

Cobus Reinach, one of the rare shining lights for South Africa on Saturday, agrees with Smith that a big improvement is needed if his side are to stop Warren Gatland's men.

"We left a lot of opportunities on the park, but that is something for us to look at, and each one of us has to look at our performance," he said.

"We can improve, and we have to ensure that we do better when we find ourselves in a similar situation. We are aligned as a squad and we know what we have to do.

"We need to execute what we want to do at a platinum standard, and everyone just needs to do their job and make sure they do it well.

"Collectively we didn’t put our stamp down, but we can fix that, and we are feeling confident going forward."