The British Lions wing has not played since returning from New Zealand with a similar problem to the one that has ruled out team-mate Gavin Henson until mid-October. Now he is targeting a similar comeback date as he battles to prove his fitness for Wales's opening game of the Autumn Series, against the All Blacks in Cardiff on November 5.
Ospreys assistant coach Sean Holley said: "It is a worry because Shane just hasn't been able to shake off the problem but it is still our hope that he will be fit for the Heineken Cup and then for Wales in the Autumn."
Williams is the sixth member of Mike Ruddock's squad to be sidelined by a groin problem.
The Wales Women's team headed to Dare Valley Country Park on a team bonding exercise as the entire squad got together for the very first time in preparation for this season's Six Nations championship which kicks off on Saturday with a clash against defending champions Ireland, in Donnybrook.
Wales Head Coach Warren Gatland discusses his team selection for the opening round of the RBS 6 Nations where he leads his side against Ireland, on Sunday. As WRU TV's Luke Brodley discovers, Gatland is fully aware of the challenges the defending champions pose
WRUTV caught up with Wales Women captain Rachel Taylor at the RBS 6 Nations launch and how a good crowd really helps boost the girls performance. Tickets for all three Women's home games at The Gnoll, Neath are available from www.wru.wales/tickets