South Africa plan to unleash Andre Nel on England for the first time in the series at Edgbaston.
The Proteas lead the four-match rubber 1-0 after a comprehensive second-Test victory at Headingley, but will be without pace spearhead Dale Steyn in Birmingham due to a broken thumb.
And coach Mickey Arthur confirmed to Sky Sports News on Sunday that Nel is Steyn's likely replacement after impressing with 3-25 in the first innings of the tour match against Bangladesh A.
"It's more than likely we'll see Andre in the next Test," Arthur said.
"He had a good bowl yesterday and picked up three wickets - bowled really nicely, in fact he's been bowling well all tour.
"It's good having a replacement like Nel in the wings to come in and take the place of a star performer like Dale."
Arthur also re-affirmed his commitment to including left-arm spinner Paul Harris at Edgbaston, despite his struggles during the first two Tests.
"He hasn't had too much work - at Lord's he was used in more of a containing role, he didn't have a huge amount of rough to work with," Arthur noted.
"And at Headingley we didn't need Harry that much - he hasn't got into his stride yet.
"We need to get his confidence levels up going into Edgbaston but, as a team, we've got a huge amount of confidence in him and what he can do for us."
England have responded to their mauling at Headingley by recalling experienced Durham paceman Steve Harmison in a 13-man squad.
"If he plays then it will provide a different challenge - a bit more pace but also a lot more scoring opportunities for our guys," added Arthur.
"At the back of our minds we thought that Harmison would come back at some point during the series.
"In our planning we did a lot of work focused on Harmison - we are prepared for anything England might throw at us."
Arthur confirmed that Jacques Kallis had fully recovered after taking a blow to the finger while fielding against Bangladesh A.
The batsman, who is the only member of South Africa's top order without a score in the opening two Tests, was taken to hospital for a precautionary X-ray, which came back all-clear.
The tour match at New Road concludes on Sunday and is followed by back-to-back Tests at Edgbaston (Jul 30-Aug 3) and the Oval (Aug 7-11).