South Africa's next two Test series are like cup finals: Bavuma

South Africa's home Test series against Sri Lanka and Pakistan over the next six weeks could possibly be considered like cup finals as the country bids to reach the World Test Championship showpiece, captain Temba Bavuma said on Tuesday.

A clean sweep of the two-match series against Sri Lanka, which starts at Kingsmead on Wednesday, and the two tests with Pakistan from Dec 26, would put South Africa into June's final at Lord's.

"We have four games left in our Test Championship (campaign), and every game is as important as a final. The guys are excited and I think you should be seeing some good stuff from the guys," Bavuma told a press conference.

South Africa have made three changes to the side that won by an innings and 273 runs in Bangladesh at the end of last month.

Bavuma returns after an elbow injury to bolster the batting while seamers Gerald Coetzee and Marco Jansen are added to the attack led by Kagiso Rabada.

"Looking at the wicket, we feel that if it does turn, it'll probably be at the end of the game," the skipper explained.

"Considering the weather as well, I think probably the seamers will come into play and be quite confident in our all-out attack.

"We understand what has brought us results and we want to concentrate and focus on that as much as we can. We know we are getting closer to what we want to achieve," he added.

Sri Lanka are also chasing a place in the final and can stay on course if they win the two tests in South Africa and then have success at home over Australia in February.

"If they are vulnerable against fast bowling, then they wouldn't be third in the (Test Championship) log," Bavuma said.

"Fast bowling will be a thing, playing against South Africa, but I'm sure they'll be backing their preparation to be able to have answers to that challenge.

"We know that we're going to have to be at our best," he added.