Johannesburg - Lock Johann Muller and prop Coenie Oosthuizen sat out the morning training once more on Tuesday, but should be cleared to leave with the Springbok team on the away leg of the Castle Tri-Nations on Friday, said Springbok coach Peter de Villiers following training.Both players have been on the sidelines since Thursday: Muller has a hamstring strain and Oosthuizen a sprained ankle. "Coenie is still nursing his ankle," said De Villiers. "He was tested this morning and came through and he'll be OK. Johann should be fine - we're just being cautious with injuries."Flanker Heinrich Brüssow also sat out training on Tuesday and De Villiers said he was being closely monitored. "We're being especially cautious with Heinrich," he said. "Every time he has come back from injury he has been pushed back too early and maybe we did the same with him last week. So we're happy to be over-cautious now - he is a valuable player and we can't let him rest enough."I'm hopeful he can play but I won't push him because he is one of those players that you build a team around."CJ van der Linde - who was added to the squad as cover on Monday - took part in his first full field training session on Tuesday."CJ has surprised me," said De Villiers. "He came through yesterday morning's fitness session very well and has trained again today so he is looking good. He'll train again tomorrow and then we'll make a decision."Gerhard Mostert also joined the squad on Monday as cover for Muller.