James, who yesterday agreed a two-year deal with Harlequins, is named in the Barbarians team that face Wales at Bristol's Ashton Gate in Ruddock's first game in charge.
It is two years since the British Lion last played for Wales after falling out of favour with Steve Hansen.
Any comeback has been put on hold as he battles back from a string of injuries, including total shoulder reconstruction that kept him out of the game for seven months last year.
But Ruddock reckons tonight's game will be a major step forward for the 40-times capped wing.
"I'm very pleased to see Dafydd involved," he said. "He's had plenty of problems with injuries and especially the problem with his shoulder that effectively ruled him out of the tour.
"So it's good news to see him back slightly earlier than expected, especially for Wales."
Meanwhile Darren Morris has been forced to put his Wales comeback on hold after withdrawing from tonight's game.
The rejuvenated Leicester prop, last capped in 2001, is required for Saturday's wild-card final at Twickenham against Sale Sharks so is unavailable but will still tour Argentina and South Africa this summer.
Morris is seen as the answer to Wales' scrum, an area that Ruddock has immediately spent time concentrating on this week.
"We've been working hard up-front with a lot of emphasis on the scrum. We've been concentrating on body positions and technique, which is a big factor for us," said Ruddock.
"Our next two games will provide us with two very contrasting styles, which is ideal for our first games together.
"The Barbarians will obviously play with width and speed while Argentina will look to take it on up-front. So it's going to be very interesting."
Ospreys youngster Gavin Henson starts at centre in place of the injured Iestyn Harris while the Baa-Baas feature France's Grand Slam pair Olivier Magne and Damien Traille.
Wales: G Thomas; R Williams, S Parker, G Henson, S Williams; C Sweeney, D Peel; D Jones, M Davies, A Jones, B Cockbain, G Llewellyn, C Charvis (capt), M Owen, J Forster.
Replacements: H Bennett, G Jenkins, P Sidoli, Dafydd Jones, M Phillips, N Robinson, H Luscombe.
Barbarians: B Reihana (Northampton and New Zealand); D James (Warriors and Wales), D Traille (Pau and France), N Grey (Waratahs and Australia), B Paulse (Stormers and South Africa); M Burke (Waratahs and Australia, capt), N de Kock (Stormers and South Africa); O Le Roux (Sharks and South Africa), M Sexton (Ulster), R Bands (Bulls and South Africa), B Mika (Auckland Blues and New Zealand), M Connors (Northampton and Australia), O Magne (Montferrand and France), A Vos (Harlequins and South Africa), E Miller (Leinster and Ireland).
Replacements: A Oliver (Otago and New Zealand), C Visagie (Saracens and South Africa), O Finegan (ACT Brumbies and Australia), A Persico (Agen and Italy), M Robinson (Northampton and New Zealand), D Humphreys (Ulster and Ireland), T Castaignede (Saracens and France).