Ruddock goes into the match without first-choice midfield pairing Gavin Henson (groin) and Tom Shanklin (knee), while leading contender Sonny Parker is battling a hamstring injury. The Blues' Jamie Robinson is still finding his feet after a year out with a knee injury and the Dragons' Hal Luscombe is out of the equation after breaking a thumb against Edinburgh on Friday night.
Ruddock has the choice of the Dragons' Ceri Sweeney in the No. 12 jersey, while veteran Mark Taylor may earn a recall if Parker fails next week's fitness test. Skipper Gareth Thomas played at outside centre for Toulouse on Saturday and may move from fullback to fill the problem area.
World-class prop Gethin Jenkins (shoulder) will also miss the autumn Test series, while doubts linger over Lions star Ryan Jones after he injured a shoulder against Bath a week ago. Ironically, the man in the Bath No. 8 jersey that day is being tipped as Jones's replacement in the Wales lineup.
Gareth Delve has been tipped as a Wales star for several years, but a serious shoulder injury meant his 2003 match against the Barbarians is his only match in the red jersey. But after an eye-catching performance in Bath's Powergen Cup victory over the Ospreys, his name is back in the headlines.
"I got a text from Scott Johnson after the Ospreys game, asking if Gareth was available for Wales squad training," Bath coach John Connolly said. "Gareth is a big, strong man. He's incredibly athletic, he's a massive ball-carrier, a good defender and he has the physicality for Test rugby.
"I think Gareth will be involved in the autumn. Ryan Jones is a good player, but he took another knock against us so you don't know. And Colin Charvis is competing with Gareth - I think Charvis is an openside flanker. I think you'll see Gareth in the 22 for the autumn Tests."
Connolly said the most exciting thing about Delve was that he still had a lot of improvement in him after his horror run of injuries.
"Gareth is definitely on an upward spiral - he didn't play for three years and it's always going to take a year to come back into it," the Australian said. "He came into some form slowly last year and he's really stepping up to the mark this season. Against the Ospreys, he was the best backrower, and the best thing is that you know he has a lot of improvement in him."
Wales Head Coach Rob Howley talks to WRU TV's Sebastian Barrett about the 36-man squad he has just named for the forthcoming Under Armour series, which includes two uncapped players, Ospreys duo Sam Davies and Rory Thornton.
Head coach Rowland Phillips is deligthed he can now call BT Sport Cardiff Arms Park home for his Wales Women's side, who launch their international season next month with games against Scotland and UK Armed Forces in the heart of the capital city.
Wales Sevens star Sam Cross has put his home town club of Brynmawr on the map after winning a silver medal at the Rio Olympics with Team GB. His club have now honoured him by naming their players bar after him, as WRU TV discovered at the official launch, recently.
One of the newest members of the Principality Premiership, Bargoed admit it's proving to be a steep learning curve at the highest level, but are determined to become a force to be reckoned with. WRU TV visited the club last weekend when they took on Llanelli.
Table-topping Aberavon travel to north Wales to tackle RGC 1404 as both teams defend unbeaten starts to the season in the Principality Premiership. WRU TV's Graeme Gillespie visited the Wizards to see how their preparations were going for the game of the weekend.
The Half a Game initiative is currently sweeping across Wales and proving a major success. The scheme aims to give every young player at least half a game every weekend. WRU TV recently visited a festival in Narberth where clubs have fully embraced the initiative.
Both Bargoed and Swansea were seeking their first win of the Principality Premiership season this afternoon. It proved a fruitful day for the hosts - not only did they win, but Bargoed claimed a try bonus point.
Cardiff managed to keep their unbeaten record at home intact, but only just as Bridgend made them work extremely hard before the Blue and Blacks secured a hard fought Principality Premiership win at the BT Sport Arms Park last night.
Former Wales back row Andy Powell gives a guided tour of The Wern, home of Merthyr RFC, who are determined to prove a lot of people wrong and make their mark in their first season in the Principality Premiership.