The former scrum-half cum wing was converted to outside-half by Springbok head coach Peter de Villiers last autumn and is expected to wear the No10 shirt against the Lions this summer.
Pienaar has been running on his own for the last fortnight but his possible return in Saturday's clash with the Highlanders will depend on how he fares in team training and contact sessions during the remainder of the week.
The news comes as a huge boost to de Villiers who saw his country's 2007 World Cup winning fly-half Butch James ruled out of this summer's Lions tour with a serious knee injury.
Without James as an option for the Boks' fly-half role, de Villiers would likely turn to Pienaar's maverick Sharks team-mate Francois Steyn or the more consistent but less exciting Willem de Waal, Peter Grant or Morne Steyn if his star man fails to recapture his form on his return to competitive action.
Bok fans, and indeed Sharks supporters who have seen their team slip to fourth in the Super 14 standings without their favoured No10, will be hoping Pienaar simply fits back into proceedings effortlessly as the season starts to reach boiling point.