JP Duminy has been released from South Africa's squad for the last two Tests in England. Duminy had been dropped for the second Test at Trent Bridge, which South Africa won by 340 runs to square the series, after managing only 17 runs across two innings in the first at Lord's. South Africa have opted to keep Aiden Markram as batting cover instead.

Markram, the 2014 Under-19 World Cup winning captain and Titans opener, was part of the South Africa A squad that toured England earlier in the summer and initially included in the squad to cover for the absence of Faf du Plessis, who missed the first Test following the birth of his daughter. Markram was expected to leave the group and begin preparations for the new season once du Plessis returned but he was asked to stay on for the second Test and will now remain with the squad even longer after Duminy's departure.

Though Markram is unlikely to play, with South Africa opting for six specialist batsmen and Theunis de Bruyn ahead of him, the selectors are hopeful he will gain valuable experience from spending time with the national side. As a result, Markram will miss South Africa A's 50-over triangular competition against India A and Afghanistan A, which starts on Wednesday, and has been replaced by Jon-Jon Smuts in the squad. Even if Markram stays for the entire duration of the tour, he will return home in time for the two four-day matches against India, which will give him more long-format experience.

The investments being made into Markram and de Bruyn suggest that the end of Duminy's nine-year Test career is nigh. Duminy last scored a century in January, against Sri Lanka but has only made 121 runs in eight innings since then and his inconsistency has cost him his place. Quinton de Kock has replaced Duminy at No. 4 in the line-up with South Africa adjusting their team balance to accommodate for two allrounders, Vernon Philander and Chris Morris, in the lower middle-order.

Philander and Morris form half of a four-pronged pace pack, which will welcome back Kagiso Rabada for the third Test. Rabada sat out Trent Bridge after being suspended for an accumulation of demerit points and spent his time on the sidelines working on his craft. Despite being one of South Africa's busiest players, Rabada did not put his feet up but bowled before play every morning to maintain the same workload as he would have had if he'd played the march.

"He bowled his overs, he got his workload up so he will be raring to go," Charl Langeveldt, South Africa's bowling coach, said. "He was disappointed with what happened but he learned a lot from that. You need to learn from it so it doesn't happen again. He said come Thursday I want to be ready for the next Test. KG is one for stepping up, taking his game to the next level. He is a youngster with lots of energy. I've got no doubt he will step up."

Langeveldt is not a selector but indicated Rabada would be a straight swap for Duanne Olivier, who struggled in seamer-friendly conditions at Trent Bridge. He was expensive in both innings and could not find the right line but that did not dim an otherwise exceptional South Africa performance. Vernon Philander nagged with subtle movement, Morne Morkel was difficult to get away and Morris was quick but it was the improvement in their discipline that was most notable.

After bowling 10 no-balls, two of which resulted in wickets at Lord's, South Africa die not overstep at all at Trent Bridge and Langeveldt admitted they put special emphasis on getting that right.

"It's a mentality. When you come to the nets, you need to stay behind the line," he said. "We spoke before the Test series as well. I said to the guys: you've been doing this for years, you are professional, it's a basic thing, you need to stay behind the line. Sure, there will be days when you over-stride, when you got for the effort ball. But we've always been strict. The more you bowl, the better you get at it."

South Africa have taken the more-is-more approach in preparation for the third Test. While England opted not to train until Tuesday, South Africa had a full session at The Oval on Monday. It was the first session they have had in two weeks with their coach Russell Domingo, who has returned to the camp following the death of his mother after the Lord's Test.

There is still no certainty over Domingo's future, after the panel appointed by CSA to recommend a candidate for the position of head coach was delayed in its work. Domingo's contract expires at the end of the ongoing Test series and he has reapplied for the post.