Steyn, who sustained the injury while fielding a ball that was driven back to him off his own bowling during the second test at Headingley on Monday, was expected to play with the injury but the specialist advised that it would be too much of a risk of incurring further damage to the thumb.

With South Africa 1-0 up in the four-match series, the injury to the bowler ranked second in the test world rankings is a major blow to the Proteas’ hopes of winning their first series in England since 1965.

“Dale has sustained a fracture on the base of his left thumb and will see an orthopaedic surgeon to have a cast put on and it will be on for between two and three weeks, then we will take another x-ray and take a decision from there,” Moosajee told reporters at Worcester, where South Africa were playing Bangladesh A.

“If it doesn’t heal in time he may (miss the fourth test at The Oval starting August 7) but we are giving ourselves a window for him to be re-assessed in two weeks. The risk for Edgbaston was that if he played he might have done further damage and then needed surgery.”

A team spokesman earlier said there “was no cause for alarm” but the seriousness of the injury now means that Andre Nel or Monde Zondeki will come in for Steyn, who claimed seven wickets in the second test.

Coach Mickey Arthur said he was confident that the strength in depth in the squad would allow South Africa to adequately replace Steyn.

“Missing a player of Dale’s calibre is a blow,” Arthur said, “but I feel we have such good depth with the likes of Andre Nel and Monde. Nel is probably next in the queue. That was why I was strong on wanting good reserve strength with experienced players who know about the intensity of test cricket.”

Meantime, spinner Paul Harris was cleared to play in the match at Worcester after he had an x-ray on an elbow injury after slipping in the bathroom in his hotel room. He suffered minor ligament damage but not enough to prevent him bowling.