"I'm running out of time to get on the Australian tour and further my goals for the Rugby World Cup," said Henson. "I've just got to hope to get back to playing some sort of part and see where that takes me.
"It's wait and see time, I'll have to look at it with the physio every Monday and hopefully one day I'll get up and the pain will have gone."
As well as the two-Tests Down Under this summer, Wales also have three Rugby World Cup warm-up matches to play. After travelling to Twickenham to face England they then host Argentina and France at the Millennium Stadium in August in the Invesco Perpetual Summer Series.
The first big date Henson will miss is the Ospreys' EDF Energy Cup Final against Leicester Tigers at Twickenham on Sunday15th April 2007. He will also miss out on their tilt for the Magners League crown.
"This effectively rules Gavin out for the remainder of this season. He has made a massive effort to get himself available for the EDF Energy Cup Final but, as is often the case with this type of injury, there is no substitute for prolonged physiotherapy," said Ospreys Physiotherapist Brian Downey.
"Our focus will now be on getting Gavin back to fitness as soon as possible, that is likely to take six to eight weeks, which means his Ospreys season looks to have ended."