Rizwan and Irfan both suffered hamstring injuries in the third match in Rawalpindi, where a second-string New Zealand side won by seven wickets to level the five-match series 1-1
Boult, the left-arm New Zealand speedster, currently heads the bowlers' list with 21 wickets from eight matches with Starc hot on his heels with 20 scalps from seven outings.
Boult's compatriot, opener Martin Guptill will have a chance to go atop the batting ladder which is presently occupied by Sri Lankan great Kumar Sangakkara having made four back-to-back centuries in the tournament.
Guptill is nine runs behind the prolific left-hander with 532 runs from eight games with a batting average of 76. The willower also boasts of the highest individual score in the history of the World Cup as he smashed an unbeaten 237 against the West Indies in the quarter-finals.