South Africa v England, 4th Test, Centurion January 20, 2016

Cook set for debut as Rossouw released

Stephen Cook talks with Russell Domingo © Getty Images

Stephen Cook has moved a step closer to making his Test debut against England in Centurion after Rilee Rossouw was released from South Africa's squad to play for his franchise, Knights, in the fifth round of the Sunfoil series which starts on Thursday.

Stiaan van Zyl, the incumbent opener alongside Dean Elgar, was let go from the squad yesterday after his struggles during the first three Tests where he had a top score of 33 in five innings. The one remaining stumbling block for Cook, a specialist opener who topped the first-class runs charts last season and has scored two centuries and a fifty from three games this summer, would be if South Africa deploy wicketkeeper Quinton de Kock in the opening berth in order to make room for JP Duminy in the middle order.

De Kock missed the Wanderers Test with a knee injury picked up walking his dogs but passed a fitness Test on Wednesday afternoon to be available for selection*. South Africa were pondering moving de Kock into the top two in Johannesburg before the injury he suffered on the eve of the game.

The desire to include Duminy in the middle-order is two-fold. Not only does he offer a part-time offspin but he is coming off the back of a career-best unbeaten 260 for Cape Cobras, scored the match after he was dropped from the Test XI in Cape Town. Room for Duminy can still be found without moving de Kock up the order if South Africa sacrifice Faf du Plessis, who has been among their misfiring men.

Whichever route South Africa take, Elgar will have a new opening partner and is well aware of the qualities Cook would bring.

"Cookie has been knocking on the door for a long time. With a lot of domestic performances he's put in, you cant not notice what he has done in the last two or three seasons. He's done very well for the Lions. He has put up his hand and put a lot of pressure on the openers," Elgar said. "We've opened for the A side. It's an exciting time for Stephen and I know he is looking forward to it. A lot has been written in the media about he never gave up hope of playing for South Africa."

Elgar remained supportive of the axed van Zyl, a regular No. 3 and still believes he has an international future. "It's unfortunate that Stiaan is the guy thats been left out. I feel for him because he was asked to do a job that was foreign for him," Elgar said. "I feel it was a position Stiaan was very capable of doing. I. I feel for him because I know what it's like being in bad form. I don't really have much to say on him opening him opening the batting, but I do sympathise with him."

Hardus Viljoen, the fast bowler who made his debut at the Wanderers and struck with his first ball in Test cricket when he had Alastair Cook caught down the leg side, has also been released from the squad. It now appears likely that the decision over the bowling combination is two from Chris Morris, Kyle Abbott and offspinner Dane Piedt. The inclusion of Piedt would aid in maintaining the four players of colour if Duminy was not recalled.

*January 20, 3.10pmGMT: This story was updated with news of Quinton de Kock's fitness test

Firdose Moonda is ESPNcricinfo's South Africa correspondent