Pakistan bowling coach Azhar Mahmood said the remaining Pakistan batsmen would need to follow the example of De Kock and Hashim Amla.
Set to make a daunting 381 to win, Pakistan were 153 for three at the close, needing another 228 runs.
Sarfraz said the loss of five wickets on the first morning after his side were sent in had put Pakistan in a position from which it was difficult to recover.
Pakistan were bowled out in the last over of the third day for 294 on Saturday, leaving South Africa 41 runs to win.
Shan Masood and Asad Shafiq shared a century partnership as Pakistan fought to avoid an innings defeat on the third day of the second Test against South Africa at Newlands on Saturday.
Dale Steyn, Vernon Philander and Kagiso Rabada took a wicket each.
Pakistan were 76 for four at lunch after winning the toss and batting on a well-grassed pitch on a hot day.
Pakistan appeared set to build a huge lead before collapsing from 286-3 to lose their final seven wickets for the addition of just 62 runs.
Shafiq made a steady 104 and Azhar notched a solid 134 as the duo punished New Zealand during their relentless 201-run stand for the fourth wicket
Azhar Ali registered his 15th hundred and first since May last year.