If surgery is required then 23 year-old Henson will miss Wales's Autumn International series plus their RBS Six Nations campaign as well as the majority of the domestic season with the Ospreys.
The British Lion has flown to the renowned Hans Muller-Woolfhart clinic in Germany for a diagnosis and will discover his fate when he joins up with his region for training in France next week.
The Ospreys star was at the centre of his region's Celtic League triumph and Wales's Grand Slam-winning side last season despite playing for most of it while receiving a prolonged course of anti-inflammatory injections.
The news comes as a bitter blow to Henson following an indifferent tour to New Zealand during which he suffered heartache when left out of the Lions' line-up for the first test against the All Blacks.
Ospreys Team Manager Derwyn Jones has played down the significance of Henson's visit to Germany saying: "Gavin has got a groin problem. He is just going to get it checked out."