Pakistan captain Sarfaraz Ahmed has won the toss and sent South Africa to field first in their 2019 ICC Cricket World Cup match at Lords.
Pakistan have only three points from five games and to make the semi-finals they are likely to need to win their four remaining games and improve their net run-rate, while hoping other results go their way.
Pakistan pace-man Riaz insists his team-mates realise the importance of the do-or-die game and he hopes displaying a united front against South Africa will spark a strong performance.
"We have to lift ourselves," Wahab told reporters. "We are each other's strength. We are all good friends and know that only 15 of us can lift the team which not even our family members can do."
Pakistan's defeat against arch rivals India last weekend sparked a depressing few days, not only for the team but also millions of fans back home.