Roberts, Halfpenny and Davies all suffered medium-term injuries
Wales centre Jamie Roberts faces six weeks on the sidelines, after injuring his elbow, and is in a race against time to be fit for the Six Nations.
Roberts hyper-extended the joint during Wales' 12-14 loss to Australia last week and is scheduled to see a specialist.
He is expected to miss the Blues' remaining European Cup pool fixtures against Montpellier (home and away), Toulon and Sale Sharks.
The injury will also hinder Roberts' preparations for the Six Nations, with Wales due to begin their title defence against Ireland at the Millennium Stadium in Cardiff on February 2.
Roberts only recently returned to international duty after a long period out of action following surgery on his knee.
His club, the Cardiff Blues, have been unlucky to pick up a raft of injuries in the last few weeks.
Roberts, Leigh Halfpenny and Bradley Davies all suffered medium-term injuries while on international duty with Wales.
Michael Paterson, Dan Fish, Andi Kyriacou and Tom James all picked up injuries in our last two matches against Zebre and the Ospreys.
Halfpenny suffered a severe stinger in the match against Australia and is receiving on-going review by specialists.
Davies suffered concussion in match against New Zealand, when he was knocked out by a cheap shot from behind by All Black hooker Andrew Hore - who was subsequently given a slap on the wrist (five-week ban).
Davies is expected to be back in training next week.
Kyriacou suffered concussion against Ospreys and is expected to be back week leading up to Scarlets or Dragons match
Paterson fractured a little finger against Ospreys and underwent surgery on Thursday. He is expected to return in four to six weeks.
Chris Czeckaj is recovering from a foot ligament injury and will undergo surgery to remove a pin next week. He is expected back early January.
Dan Fish suffered a shoulder nerve palsy in the match against Zebre and will be seeing a specialist.
Tom James fractured his big toe. He underwent surgery to remove the pin on Wednesday and is expected to return in six weeks.