The reigning Grand Slam champions are already set to do without Luke Charteris, Rhys Priestland and Aaron Jarvis, who are out with long-term injuries.
Now there is some doubt surrounding Jones after he sustained a dislocated thumb on Sunday during the 15-15 draw with Leicester Tigers in the Heineken Cup.
The Ospreys boss Steve Tandy has revealed Jones suffered the injury at the Liberty Stadium and now it will be a waiting game to see whether the utility forward will be fit to play against Ireland at the Millennium Stadium on February 2.
He said: "Ryan has gone off to hospital.
"I think he has got a dislocation of his thumb. It may have popped through the skin as well."