Ryan Jones face an anxious wait with his injury while Stephen Jones is expected to be back to full fitness next week.
Ryan Jones's dream of playing in a World Cup are hanging in the balance after a niggling calf injury could rule him out for up to two weeks.
The Ospreys No 8 injury woes have left the Wales management with a headache as head coach Warren Gatland could be forced into sending out for a replacement just after one game.
Gatland admitted he is left in a quandary and will have to assess the situation after Sunday's opening World Cup clash against defending champions South Africa in Wellington.
"The thing is if we do replace him and if he does recover in two weeks and we pick up another injury, you can't recall that player."
Jones missed selection in the Welsh squad for the 2003 World Cup and withdrew from the 2007 tournament with a shoulder injury.
"We just want to see how Sunday goes and hopefully we won't pick up any injuries and we've just got to give (Jones's') injury a little bit more time to settle," Gatland added.
"It's a long tournament and we've got to make sure we make the right decision there. Obviously, if we pick up injuries on Sunday that's going to change our thinking, so we have to see what happens."
Jones won selection in Wales' 30-man World Cup squad after convincing team medical staff of his fitness after playing only 30 minutes in three warm-up matches, missing wins in Cardiff over England and Argentina.
On the Welsh squad's arrival in New Zealand he had been confident of breaking his World Cup jinx.
"There is always the moment where you think 'oh no, not again'," Jones said. "You never know what will happen.
Playing at the World Cup is always something I have dreamed of doing and now I am really looking forward to it.
"The fact I have never been to a World Cup before means I have nothing to compare this to. But I want to experience one. I want to do my best for my team and my country," he added.
Gatland said prop Gethin Jenkins and flyhalf Stephen Jones, who were not considered for the South Africa match because of injuries, were expected to return to full training from next week.
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.
WRU TV: Hear from inside the Wales camp as Neil Jenkins discusses this weekend's clash with South Africa and how the squad are looking to put in a strong performance to round of the 2016 Under Armour Series