Jacques Kallis: still vital to South Africa, but not risked for Twenty20 © Getty Images

Incoming South African selection convenor Joubert Strydom said that Jacques Kallis's omission from the hosts' Twenty20 World Championship squad was done in the light of the country's "nightmare" schedule in the next 18 months.

South Africa go to Pakistan, Bangladesh, India, England and Australia in the next 18 months and Strydom said: "Jacques is a crucial part of our Test and one-day plans and we don't want to sacrifice him in the Twenty20 format".

Kallis, who has scored at better than a run-a-ball in his half-dozen Twenty20 appearances at domestic and international level, is a relatively slow starter at the crease and found himself in the middle of a storm over his perceived slow scoring during the World Cup.

In 20-over cricket, Kallis would probably be best suited to moving up to the top of the order, but Strydom said South Africa had several other options for those positions and, although the allrounder's bowling skills would be missed, it was not worth risking him in the competition.

"Once we decided to rest Jacques, there was no debate about how heavily we rely on him as a bowler or whether he could bat up front ahead of quite a few guys competing for places there."

Strydom also explained the absence of any recognised death bowlers in the South African squad.

"In 20-over cricket, if you're bowling in the same area all the time, even the blockhole, it becomes very easy for the batsman. He knows which length to expect and he can line you up

"We will be experimenting a bit. We will be using guys who take the pace off the ball, like Graeme Smith or JP Duminy, while also trying a guy like Morne Morkel for the death-type bowling. Because he is so tall, he bowls a different length to most bowlers and he is able to push the batsman back.

"In limited-overs cricket now, you see guys like Shaun Tait and Lasith Malinga being effective when they bowl a bit shorter. A lack of bounce or excessive bounce is effective.

"If you're going to be aiming for the blockhole, then it has to be with pace and reverse-swing."