South African captain Graeme Smith was "80 to 85 per cent fit" on Wednesday, team physiotherapist Shane Jabaar said two days before the third Test against the West Indies, which starts at Newlands on Friday.

Smith's fitness is the only major concern for the high-riding South Africans, who won the first Test in Johannesburg by 189 runs and the second in Durban by an innings and 65 runs.

Smith suffered an injury to his right hamstring when he slipped on a damp outfield on the first day of the Durban Test.

Although he continued to field in the first innings and then batted, he did not field in the second innings in what was described as a precautionary measure.

But the South African captain walked stiffly when he attended the after-match press conference on Monday and Jabaar confirmed on Wednesday he was in a race against time.

"We have worked on him this morning and we will do so some more work after an optional practice this afternoon. I am hoping that he will be 100 per cent by tomorrow (Thursday), " said Jabaar.

If Smith cannot play, vicecaptain Mark Boucher will take over the captaincy and Gary Kirsten, who has batted at number five in recent Tests, will probably move back to his former position as an opening batsman.

Martin van Jaarsveld would probably come into the middle order. Van Jaarsveld made 73 and 15 when he replaced Kirsten, who attended the birth of his first child, in the first Test.

Left-arm spinner Paul Adams is expected to play at Newlands ahead of all-rounder Andrew Hall,

who was part of an all-seam attack in Durban.

Selection convenor Omar Henry said: "History has shown that a spinner is essential at Newlands."

While South Africa can feel confident regardless of Smith's fitness, there are worries aplenty for the West Indians, despite captain Brian Lara's assertion after the second of four Tests there would be no repeat of the whitewash defeat the players from the Caribbean suffered in five Tests in South Africa in 1998-99.

There are fitness concerns over

batsmen Chris Gayle and Shivnarine Chanderpaul and bowler Corey Collymore but the biggest worry for Lara is the poor form of his bowlers.

Lara said the batsmen needed to be more consistent, but that he was encouraged by the form of his top order.

"Five years ago we were beaten in just over two days in Port Elizabeth and in five matches we didn't get a single century. We have three (centuries) already in this series."

He said the hundreds by Sarwan and Chanderpaul in the second innings in Durban had given the team heart.

But he acknowledged that bowling was a problem.

"Your backs are against the wall when the team batting against you is scoring at four runs an over. We've got to be able to pull things back and be more consistent in line and length."

Lara said bowling shortcomings were easier to solve than lack of form by batsmen.

"We've just got to work hard over the next few days to put things right," he said.

Other than bowling more steadily, it's difficult to see how the West Indies can come back.

The inexperience of promising fast bowler Fidel Edwards has been shown up against good batsmen on good pitches, while Mervyn Dillon, the most experienced bowler in the side, has lacked the pace to trouble the South Africans in the first two Tests.

The West Indies will probably want to play a spinner at Newlands but the only specialist slow bowler in the squad is uncapped left-armer Dave Mohammed, who was expensive and unimpressive in his only tour match, against Border.

The West Indian batting lacks depth. Opener Wavell Hinds has been hopelessly out of form during the tour and if either Gayle or Chanderpaul cannot play, the West Indies will have to choose between Carlton Baugh and uncapped Dwayne Smith as a batsman.

Baugh played in Durban without looking likely to play a long innings and both he and Smith are aggressive players whose techniques could be exposed by the South African bowlers.

The pitch at Newlands usually is good for batsmen, but with enough pace and bounce to keep fast bowlers interested, while spinners usually come into play towards the end of a match.