Harmer's call-up a warning to Tahir

Offspinner Simon Harmer has been added to South Africa's Test squad for the New Year's Test against West Indies in Cape Town, following Imran Tahir's expensive showing in Port Elizabeth. Although coach Russell Domingo suggested Harmer's inclusion was more to have a look at what he could offer in future, Harmer could be in line for a debut because other spin options are scarce.

Robin Peterson will be out of action for another week as he recovers from a cut to a finger on his bowling hand, sustained three days before the Port Elizabeth Test, while Dane Piedt, who debuted in Harare in August, has only just made his first-class comeback after a shoulder injury.

Piedt is playing in the ongoing match between the Cobras and Knights in Paarl which has turned into a run-fest. He bowled 47 overs in the first innings and had a return of 1 for 162 and, even though his workload was high, the South African management seem to want him to get more game time before returning to international cricket. "It would be good for him to get some overs under his belt and maybe play a little bit more," Hashim Amla, South Africa's captain said.

That leaves Harmer, who finished second on the wicket-takers' list in the 2013-14 season behind Piedt, as next in line for a maiden Test appearance on the surface which should offer the most turn of the series should the selectors decide a change is required. Newlands is usually the place spinners contribute most in South Africa and despite the support offered to Tahir by his team-mates - Amla praised him for getting into the West Indies tail and Morne Morkel said he is "always in the game" - his lack of control may cost him his place.

Tahir was drafted into the Test squad on Wednesday, after Peterson was ruled out, and came in off the back of a six-wicket haul for the Dolphins. He had not played a Test since July and was initially dropped for this series. His performance in Port Elizabeth highlighted the issues that have blighted his Test career with his inconsistency leading to an economy rate of over four an over.

Harmer, if chosen, would be required to be much tighter. Although his economy rate is not as impressive as Piedt's, he has acted as both an aggressor and a container for the Warriors and also has a first-class century to his name if South Africa are concerned about bolstering their batting.

One issue which could keep Harmer from playing is South Africa's wariness over making too many changes. Already, they have had two debutants, Stiaan van Zyl and Temba Bavuma, in two matches following injuries to JP Duminy and Quinton de Kock and are trying to achieve stability during a period of transition following the retirements of Graeme Smith and Jacques Kallis.

With the series yet to be won, Amla indicated they will not use Newlands for experimentation although they may have been tempted to if they were 2-0 up. "I don't think too much will change," he said. "If we had won, we would have had more scope to try something."

The biggest beneficiary from that approach will be opening batsman Alviro Petersen, who will mark two years since his last Test century in the third Test, and is facing pressure from van Zyl. It will also mean South Africa will field their strongest attack consisting of Dale Steyn, Morne Morkel and Vernon Philander, and there will likely not to be space for a recall for Kyle Abbott or a cap for Kagiso Rabada.