South Africa bowler Dale Steyn has been ruled out of Thursday's World Cup opener against England.
The paceman, 35, injured his shoulder during the recent Indian Premier League season and will not be risked at The Oval.
"He's not quite ready yet, not far away but not ready," said head coach Ottis Gibson.
"We think with a six-week tournament there's no real need to force the issue just now. He won't be available for the first game. We've still got 14 others so we'll choose from them."
The Proteas have also had injury concerns over their two other main strike bowlers, Lungi Ngidi (side) and Kagiso Rabada (back), though both played in the warm-up win over Sri Lanka last week.
All-rounders Chris Morris and Dwaine Pretorius are in the frame to replace Steyn.
Fast bowler Anrich Nortje was ruled out before the tournament because of a thumb fracture sustained in training.
South Africa have never won the World Cup and Gibson is in the unenviable position of having it in his contract that he must guide the side to a maiden title.
Gibson though played it down and said he was relaxed about the situation facing him.
"I don't feel that at all," he said. "At the end of the day, it's just cricket. If we play well enough to win, we could win. If we don't, life goes on."
Gibson has had two previous stints with tomorrow's opponents England as a bowling coach, his most recent stint coming to a close at the end of 2017.
He said he is not surprised by their recent success in the 50-overs format that has set them up as pre-tournament favourites.
"I enjoyed both my stints with England," Gibson added. "I know a lot of the guys in the dressing room.
"The way they are playing at the moment, I was very much involved in that for the first two years and they have gone on two years since I left."
Meanwhile, England captain Eoin Morgan is confident he and his teammates are well set to begin proceedings with an impressive performance at Lord's.
Morgan has recovered from an injury scare, where he hurt his left index finger in a fielding practice session, and he said: "As a whole I was very happy with the preparation.
"When you play as convincingly as that it builds confidence in the hard work you've done both in training and in the game and the other side of it is that it gives us the afternoon and evening to switch off - not playing another close game against a strong side.
"Everyone is going to feel that anticipation and excitement of playing the first game and it will be different than any other day and I will be encouraging guys to embrace it."
England should have a full 15-man squad to pick from after an ankle injury for fast bowler Mark Wood picked up in Saturday's warm-up loss to Australia proved not to be as bad as first feared.
"It's the best possible news," said Morgan. "With Woody being a fast bowler it's inevitable we would have injuries but to come back with the scan as clear as it could be is great, so we are all ready."
Wood said: "I probably could have carried on bowling but I didn't want to take any risks with it when I knew what was round the corner, especially with my background.
"I will fully join in with practice on Wednesday and then be ready to go on Thursday if selected."
