Jones chipped his collarbone during the Ospreys' Powergen Cup defeat to Bath 12 days ago and is set to be out for at least five weeks.
Wales had originally hoped Jones, an inspirational late arrival on the Lions tour this summer, would be back in time to face New Zealand on November 5.
But the Ospreys on Friday issued a brief injury update which stated the 24-year-old is "unlikely to be fit until late November or early December".
Jones joins Lions colleagues Gavin Henson, Tom Shanklin and Gethin Jenkins on the sidelines while fly-half Stephen Jones is battling to be fit after injuring his ankle playing for French club side Clermont Auvergne.
Wales face Fiji and South Africa before ending their autumn programme against Australia and Jones will hold out hope of returning in time to face the Wallabies on November 26.
Wales physio Mark Davis had rated Henson as having an "outside chance" of making one of the later Tests, but the Ospreys maintain he will not be fit until early December.
Ruddock faces a shortage of tight-head props with Jenkins out and Worcester's Chris Horsman up in front of a Rugby Football Union disciplinary panel on Tuesday.
Horsman, who qualified to play for the Six Nations champions after completing a three-year residency period last month, must appear before disciplinary chiefs in Bristol after being cited for allegedly stamping on a Leeds opponent.