Dragons are already without Wales tight-head Dillon Lewis, who suffered a calf injury on his fourth appearance since signing from Harlequins.
The 29-year-old is out of the European games against Perpignan and Lyon, plus the United Rugby Championship (URC) games against Connacht, Cardiff and Scarlets.
South African Rob Hunt is the leading option for the number three jersey, backed up by Luke Yendle, whose last professional appearance was 14 months ago because of a knee injury, and 20-year-old Owain James.
Dragons kick off their Challenge Cup campaign on Sunday at French Top 14 strugglers Perpignan.
Lock and captain Ben Carter, hooker Brodie Coghlan and wing Rio Dyer are back after featuring against the Springboks, but number eight Aaron Wainwright has been given the weekend off.
Dragons are also assessing Seb Davies’ ankle injury, which he suffered against Leinster last weekend, but the lock or blind-side flanker faces a spell on the sidelines.
