Wales have been engulfed by a second-row injury crisis less than three weeks before launching their RBS 6 Nations title defence.
Interim head coach Rob Howley is due to name his Six Nations squad tomorrow, but the lock department has been decimated.
Alun-Wyn Jones, Luke Charteris, Bradley Davies and Ian Evans are all currently injured, while former Wales captain Ryan Jones - a potential second-row starter against Ireland on 2 February - has now joined them.
Jones, who has played Test rugby at number eight, flanker and lock, went to hospital in Swansea last night after suffering a suspected dislocated thumb during the Ospreys' 15-15 Heineken Cup draw against Liberty Stadium visitors Leicester.
"Ryan has gone off to hospital," Ospreys head coach Steve Tandy said. "I think he has got a dislocation of his thumb. It may have popped through the skin as well."