If the early diagnosis proves accurate, the 24-year-old faces six months or more on the sidelines.
As well as ruling Pocock out of the rest of the Super Rugby season, it would mean he would play no part in the Wallabies' bid to beat Britain and Ireland's elite in June and July of this year.
The Lions take on the Wallabies in Brisbane on June 22, Melbourne on June 29 and Sydney on July 6, with Pocock already identified as one of the key obstacles to their hopes of avenging their 2001 series defeat to the same opposition.
If confirmed, the news will be a huge blow to Wallaby boss Robbie Deans, who has spent much of the past week explaining just how important the Lions' series is to Australian Rugby.
A near certain starter for the Wallabies if fit, Pocock was also being tipped to take over from James Horwill as his country's captain having being appointed stand-in skipper during the Reds lock's absence last year.
And while the Wallabies are used to having to cope without Pocock given that he followed Horwill on to the sidelines for 10 straight games after picking up another knee injury in August, the news has already been met with huge disappointment Down Under.
But even if scans confirm that Pocock will be unavailable this summer, the Lions will still be up against one of the world's leading No7s in the shape of understudy Michael Hooper.
Hooper picked up three Rugby Championship man of the match awards and produced a sublime display against England when standing in for Pocock last year so the Lions still won't have it all their own way in the battle of the breakdown.
Pocock's latest injury setback could also lead to a Wallaby recall for veteran flanker George Smith, the man who replaced him in Canberra earlier today.
Smith made his first Super Rugby appearance for three years having agreed a short-term deal from Japanese outfit Suntory Sungoliath.
And while Deans suggested this week that there were no plans in place to extend Smith's 12-week contract so the 32-year-old could feature against Warren Gatland's troops, the former Toulon and Stade Francais star could yet be called upon to answer a national SOS 12 years after he last faced the Lions.