While wicket-keeper-batsman Klaasen recently notched 69 runs from 30 balls in South Africa's six-wicket win over India in the 2nd T20I, 20-year-old Mulder has played a single ODI against Bangladesh at East London in October 2017.
Reflecting on Klaasen's inclusion, Cricket South Africa (CSA) selector Linda Zondi said that the 26-year-old has been tremendously impressive and are expecting a similar kind of performance in the five-day format.
"Klaasen has been tremendously impressive in the white-ball matches he has played for the Proteas and we firmly believe he can become just as good a player in the five-day format," cricket.com.au quoted Cricket Zondi, as saying.
Klaasen will also serve as a back up to incumbent gloveman Quinton de Kock, who has returned to the squad after recovering from a wrist injury.
"He has averaged nearly 50 with the bat in Sunfoil four-day cricket this season and hit two centuries. We are also keen to have a back-up wicketkeeper to De Kock in the squad," Zondi said.
Meanwhile, Mulder's selection comes in the wake of the CSA's strategy to expand their pool of all-rounders against top quality opposition, said Zondi.
The full South Africa squad is as follows:
Faf du Plessis (c), Hashim Amla, Temba Bavuma, Quinton de Kock, Theunis de Bruyn, AB de Villiers, Dean Elgar, Heinrich Klaasen, Keshav Maharaj, Aiden Markram, Morne Morkel, Wiaan Mulder, Lungi Ngidi, Vernon Philander, Kagiso Rabada.
Image: South Africa's Heinrich Klaasen
Photograph: CSA/Twitter
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