Nel joins a lengthening injury list for South Africa

The combative 28-year-old, South Africa's top bowler in the Test series with 14 wickets, has a severe stress reaction in the second metatarsal.

"It was decided he needed three to four weeks to stop it becoming a full-blown fracture," physio Shane Jabaar said.

Nel will be replaced by Dale Steyn or Makhaya Ntini, who has had a cortisone injection in his knee and faces a test to decide if he can rejoin the tour.

Ntini flew home after being sidelined for the final Test by a tear in a tendon behind his left hamstring.

"We will not take any risks with Makhaya, although we are encouraged by medical reports around his recovery," Convenor of Selectors, Haroon Lorgat, explained.

Nel had been experiencing pain his left foot and blamed repetitive "slamming it into the ground on hard pitches."

�I had set myself goals that I wanted to achieve during this tour but I am glad that it�s not a serious injury which can keep me out of the team for a long time,� he said.

The South African bowling attack may now have to feature inexperienced duo Garnett Kruger and Monde Zondeki.

Kruger, 20, has yet to play international cricket, while 23-year-old Zondeki has played in only five Tests and eight one-day internationals.

The triangular VB Series, spanning 12 matches, begins on Friday, with South Africa entering the fray against Australia on Sunday.

Nel could conceivably be fit for the first of a possible three-match final on 10 February, but is more likely to be available when the Australians tour South Africa for a one-day series later that month.

Meanwhile, South Africa coach Mickey Arthur is confident that skipper Graeme Smith will regain form in the VB Series.

Smith averaged 25 in the Tests and made 22 in the Twenty20 defeat by Australia, followed by six in a one-day warm-up against Queensland. �

"I've looked at his technique and there's no problem," Arthur said. "He's a strong man and he handles it. �

"He's been getting through the new ball every time, which means his technique is sound. He just needs a big score and time in the middle."