Springboks coach Jacques Nienaber said Kolbe would have been released from the squad if they thought he wouldn't be ready for the later stages of the tournament.
Kolbe injured a leg soon after the side began their first training session after completing quarantine in Australia.
When announcing his side on Wednesday for the second Championship Test against Australia in Brisbane at the weekend, Nienaber said there were encouraging signs that Kolbe would soon return to team training and be in contention for the two Tests against New Zealand.
The Test on 25 September in Townsville takes on extra significance as the 100th Test played between the All Blacks and South Africa.
"Cheslin is back and running quite well next to the side of the field, but he's not someone we will ever rush back," Nienaber said.
"He hasn't done any team training as yet, but the moment he has the full range of motion and strength, and when the medical team is happy with his progress, then he will reintroduce him to team training and then a return-to-play protocol.
"As coaches, though, we are hoping he will be available by next week, or the week after. We wouldn't have kept him in the squad if we didn't think he would be ready to play some part in our games."
"It's not always an exact science, but our projections suggest he will be available for selection within the next two weeks," he said.
Nienaber said he expected lock Lood de Jager to be available for the first Test against the All Blacks once completing his seven-day recovery from concussion.
Three changes have been made to the Springboks starting side for Saturday's Test in Brisbane. Marvin Orie replaces de Jager at lock while Trevor Nyakane will start at loosehead prop with Steve Kitshoff replacing Ox Nche on the bench.