Van der Merwe, who plays for the Lions and the Cats, is named alongside recalled utility back Conrad Jantjes.
It is a much-changed Springboks squad to that which clinched the World Cup in France last month.
Os Du Randt and Bob Skinstad have retired while Percy Montgomery, BJ Botha, Jean De Villiers and Pierre Spies are injured.
Butch James, Gary Botha and Ashwin Willemse were not considered as they have all joined foreign club sides.
The Springboks will play Wales in Cardiff on November 24 and the Barbarians on December 1 at Twickenham in London.
The squad gather in Johannesburg on November 12 and leaves for Wales on November 16.
Squad: B Botha, S Burger, B Du Plessis, J Du Plessis, F Du Preez, J Fourie, B Habana, C Jantjes, R Januarie, W Julies, V Matfield, J Muller, A Ndungane, W Olivier, R Pienaar, JP Pietersen, A Pretorius, D Rossouw, J Smit (capt), J Smith, G Steenkamp, F Steyn, A van den Berg, W van Heerden, CJ van der Linde, H van der Merwe.