Wayne Pivac signed the South African No 8 this summer from fellow Guinness PRO14 side Cheetahs, but saw the forward suffer a worrying leg problem in their pre-season defeat at Bath.
There were concerns Cassiem had injured his Achilles and would face a lengthy lay-off.
But those worries have been allayed, with the 28-year-old’s diagnosis revealed as a calf problem which will keep him out for four weeks.
While Cassiem will miss the first few rounds of PRO14 action, he should be back in action at the start of October.
Confirming the news, a Scarlets statement read: “Uzair Cassiem suffered a leg injury in the pre-season friendly against Bath Rugby on Friday 24th August.
“The international Springbok underwent a scan on Tuesday to understand the extent of the injury.
“Scan results have showed that Cassiem suffered a calf injury, he should make a full recovery and return to action within four weeks.”
