Clermont Auvergne's medical staff had been tipping that Jones would make a stunning recovery from an ankle injury suffered against Biarritz last weekend. He was included in the initial squad of 24 named to play Stade Francais Paris on Saturday, but didn't make the final cut.
'It's a pity I couldn't play, because we've got an incredible crowd in, the weather's perfect and these are the sorts of games everyone wants to play,' Jones said. 'I believe I could have played, but there are still a few doubts about the ankle. The only wish you have when you're injured is to get back playing as quickly as possible.
'I really thought I would be fit for this game, but it's obviously going to take a few more days.'
A Clermont club spokesman said Jones's ankle would be looked at on Wednesday, in the hope of playing him against Castres next weekend. The delay in his return is another setback for Wales coach Ruddock, who is spending more time looking at X-rays than training videos these days.
World-class prop Gethin Jenkins (shoulder) and gifted centre Gavin Henson (groin) have already been ruled out of the autumn internationals. Scrum-half Dwayne Peel will have an ankle operation on Monday and will out of action for at least a fortnight, although understudy Gareth Cooper started on the bench for the Dragons on Saturday night.
Centre Tom Shanklin (knee) came through the Blues' loss to Wasps on Friday night unscathed, while Lions backrower Ryan Jones (shoulder) returns for the Ospreys against Bath on Sunday.
Ruddock's biggest problem next month could be at hooker. Robin McBryde has retired from rugby because of on-going neck problems, while possible replacements Rhys Thomas, Matthew Rees and Gareth Williams are all twiddling their thumbs on the injury list.
On the good-news front, Scarlets backrower Dafydd Jones (finger) is making a faster-than-expected recovery and may be available for the autumn Tests, and captain Gareth Thomas's sore shoulder is not considered a problem.
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.