Pakistan have had a miserable start to the tournament, being well beaten in their opening two group matches. Their 76-run defeat by arch-rivals and defending champions India was followed by an even heavier 150-run loss to the West Indies in Christchurch on Saturday. Pakistan next face Zimbabwe in a must-win Pool B game on March 1, which Wasim warned will be a "make or break" for them.
"I am very optimistic that they can win but if they don't they have to go back home early," Wasim told AFP. "They must feel for the people who come to the ground in numbers and millions are watching back home," added Wasim a key member of the Pakistan side that won the World Cup when the tournament was last staged in Australia and New Zealand in 1992.
The top four in each of the two pools of seven will qualify for the quarter-finals. Wasim criticised the team management and captain Misbah-ul Haq for not playing five bowlers.
"I have been screaming this for several months now but they are playing with four bowlers and weakening their strong point," said Wasim, widely regarded as the greatest left-arm paceman cricket has ever seen.
"We are using an extra batsman and yet we are unable to chase, then it's disappointing and will land Pakistan in more trouble. They must rebuild the team soon."
Pakistan dropped leg-spinner Yasir Shah, who played against India in Adelaide, from the XI that took the field against the West Indies and conceded a total of 310 for six at Christchurch's Hagley Oval. If that wasn't enough, Pakistan then recorded the worst-ever start to an innings in all one-day internationals, with their first four wickets falling for just one run. They were bowled out for a mere 150 runs in 39 overs.