Lanky Western Province lock Andries Bekker has joined suspended Bakkies Botha and Danie Rossouw (concussion) as a doubtful starters for South Africa's third and final Test against the British and Irish Lions in Johannesburg on Saturday.

In revealing an extended injury list, Bok conditioning coach Neels Liebel confirmed that three of the four locks in the squad at present are doubtful.

Bekker injured his knee in coming on as a replacement in the Springboks' series-clinching 28-25 win over the Lions in Pretoria at the weekend.

He has gone to see a specialist and a call on his availability will be made later in the week.

Rossouw, who suffered concussion when blindsided by a head-shot from Lions centre Brian O'Driscoll, will be monitoring according to Inter national Rugby Board protocol this week. However, given how heavy the knock was, it is unlikely he will be cleared.

The Bok management has also still not decided if they are going to appeal Botha's two-week suspension for an incident which many observers felt was a legal rugby playing action - in clearing out a ruck, with Lions prop Adam Jones injuring his shoulder when knocked back.

The Bok conditioning coach also revealed that Fourie du Preez felt "discomfort" after the game from a shoulder injury he suffered during the Super 14. However, they are confident he will be fit for Saturday's final showdown.

Veteran centre Jean de Villiers injured his AC joint and while a call on him has also been delayed till later in the week, they said his substitution at the weekend was more a "precautionary" measure and certainly hasn't ruled him out.

Bok coach Peter de Villiers admitted that he has given "some thought" to calling up a second row replacement, but added that they are away final medical reports and the possible appeal of Botha's suspension before making a call.

He added that there is enough "talent" in South Africa and suggested they could even just call up a Bulls lock should the need arise - without divulging which one of the remaining Bulls players could be in line.

However, Emerging Springbok lock Wilhelm Steenkamp is a Bulls player and he may well be next in line, although a call to Sharks captain Johann Muller won't be a bad decision either.

When looking at a possible replacement for the gap in the squad left by Burger's suspension, De Villiers could promoted Cheetahs flank Heinrich Brussow and call Emerging Bok captain Dewald Potgieter in as cover.