If Pocock is out for 12 weeks, it would put his Brumbies comeback on hold until a round 10 home clash against the Jaguares on April 22.
Pocock took a break from all rugby last January after playing with Wild Knights during the 2016-17 Japanese season.
Before returning to Japanese club rugby later in the year, Pocock worked on conservation projects in Africa and studied at Harvard University.
His decision to step away from the game was designed to freshen his body and mind before next year's World Cup.
The 29-year-old, who has earned 65 Wallabies caps, has twice undergone major knee surgery during a decorated career at international and Super Rugby level.
He had knee constructions in 2013 and 2014.
- AAP