Joe Launchbury underwent a fitness check while his England team-mates trained for Saturday's first Test against South Africa in Johannesburg.
The Wasps lock is expected to start the series opener at Ellis Park but his inability to practise with the remainder of the squad raises doubts over his availability.
Sam Simmonds, the Exeter number eight, also missed the session completed at Kings Park due to an unspecified injury.
South Africa batsman AB de Villiers has announced his shock retirement from all forms of international cricket with immediate effect.
The 34-year-old has been a titanic figure in the Proteas' middle order for more than a decade and will go down as one of their greatest ever batsmen.
De Villiers starred in the recent Test series victory over Australia - and only last year recommitted to representing South Africa in all formats after taking a break from Test cricket - but admitted his efforts have left him fatigued.
He said in a video on his Twitter account: "I have decided to retire from all international cricket with immediate effect.
"After 114 Test matches, 228 ODI's and 78 T20 Internationals, it is time for others to take over. I have had my turn, and to be honest, I am tired.
"This is a tough decision, I have thought long and hard about it and I'd like to retire while still playing decent cricket. After the fantastic series wins against India and Australia, now feels like the right time to step aside."
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Darren Lehmann will continue in his role as head coach of the Australia team after a Cricket Australia investigation found that he had no prior knowledge of the plan to ball tamper during the third Test against South Africa.
CA chief executive James Sutherland said that knowledge of Cameron Bancroft's attempt to manipulate the ball with sticky tape against South Africa in Cape Town was limited to three players - opener Bancroft, captain Steve Smith and vice-captain David Warner.
Sutherland said Tim Paine has been appointed captain of Australia's Test team, and said the three players involved in the ball-tampering case will leave South Africa on Wednesday.
"I want to apologise to all Australians for what took place," Sutherland told a press conference in Johannesburg. "It's about the reputation and integrity of Australian cricket and Australian sport and whether Australians can take pride in their national team.
"The key finding is that prior knowledge of the ball-tampering incident was limited to three players - captain Steve Smith, vice-captain David Warner and Cameron Bancroft.
"The three players on report, we are contemplating significant sanctions, which will reflect the gravity of what has occurred and the damage it has done to the standing of Australian cricket."
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