Ntubeni fractured a metatarsal in his left foot playing in the Stormers 28-12 Super Rugby loss to the Bulls at Loftus in Pretoria.
The Springbok tourist – who was out of action for a few weeks with a calf-muscle injury earlier in the tournament – is now set for a minimum lay-off of at least eight weeks.
“Scarra will see a specialist later in the week, but, at this stage, he will be out for at least eight weeks,” said coach Allister Coetzee on the Stormers site.
Experienced prop Brok Harris suffered a cut eye-lid (left eye) against the Bulls and is in doubt for next weekend’s home clash against the Force, but Coetzee is hopeful that front rowers Oli Kebble and Frans Malherbe (both concussion) will come back into the selection equation this week.
Wing Kobus van Wyk could also perhaps return this week, despite earlier worries about the extent of his wrist injury, whilst it is also hoped that flyhalf Demetri Catrakilis can be considered for selection after breaking his nose against the Lions last month.
“Hopefully both of the props, or – at worst – at least one of Oli or Frans will be back for the Force game,” said Coetzee.
“Schalk Burger took a knock to his lower back, but we will know more about those injuries – including Kobus and Demetri – tomorrow.
“Scarra being out, the concern over Brok and Schalk’s knock are the only concerns from the Bulls match, but our injury list remains a long one, having gone to Loftus Versfeld – a tough place to win – without 19 injured players this past weekend.
“There was plenty intent out there on Saturday night, especially in the first 20 minutes, and there’s a lot to work with (based on that).
“I know it’s not what people want to hear, but we’re busy with a process and our young players, many of whom were on debut (on Saturday), will continue to develop and learn,” added Coetzee.