Despite celebrating his 36th birthday earlier this month Williams was hoping for a possible late call up for a fourth World Cup with Wales if there were any injury problems in the back row. He is one cap short of reaching 100 for his country, although he also has five British &Irish Lions Tests to his credit.
Williams missed out on Warren Gatland's 30-strong World Cup party when the Wales coach opted to take only one specialist openside flanker - his Blues team mate Sam Warburton. But he was put on stand-by and was waiting for a call to fly out to New Zealand in an emergency.
And with Ryan Jones and Dan Lydiate carrying injuries, that call could have come at any time as Wales try to reach the quarter-finals for the first time since 2003. But with his World Cup hopes dashed, he will now have to try to regain full fitness by December to encourage Gatland to include him in his squad to face Australia in the post-tournament international at the Millennium Stadium on Saturday, 3 December.