The Llanelli Scarlets star has been ruled out of Sunday's Powergen Cup clash against Newcastle at Stradey Park after a scan revealed a "spur" on his ankle which was affecting his Achilles tendon.
Initial opinion points to a fortnight's lay-off, with Llanelli hopeful he will be fit for their October 22 European Cup opener against holders Toulouse.
"Obviously, we are disappointed that Dwayne won't be playing on Sunday," said Scarlets chief executive Stuart Gallacher.
"But it is important that we take early action to prevent a more serious injury, and we are hopeful of having him back for our European Cup campaign later this month."
Peel started all three Lions Tests in New Zealand during the summer, and was an integral part of Wales' Grand Slam success last term.
Wales kick off their autumn series by hosting the All Blacks on November 5, followed by appointments with Fiji, South Africa and Australia.
Peel's Lions colleagues, centre Gavin Henson (groin) and prop Gethin Jenkins (shoulder), are already absent for the entire November Test schedule, while wing Shane Williams has yet to begin his comeback after undergoing groin surgery.
Better news for Ruddock though, surrounds fly-half Stephen Jones, who is set to feature in Clermont Auvergne's French Championship appointment with Stade Francais, despite suffering an ankle injury last weekend.
Back-row forward Ryan Jones, having recovered from a shoulder injury, is likely to feature for the Ospreys against Bath on Sunday, and Peel's Wales scrum-half colleague Gareth Cooper is on the Newport Gwent Dragons bench at Northampton.