George North could be switched to centre if Jonathan Davies is unable to recover from injury in time for Wales' Six Nations clash with France on Friday.
Davies was ruled out of Clermont Auvergne's Top 14 match against Castres at the weekend due to a groin muscle problem.
Wales assistant coach Rob Howley revealed that wing North filled in at 13 during training on Monday morning and Davies will be assessed during an afternoon session.
Fellow centre Cory Allen is definitely out after damaging his ankle during Cardiff Blues' defeat to Leinster on Saturday, while lock Luke Charteris (knee) and fly-half Rhys Priestland (dead leg) are being monitored ahead of the game against Les Bleus at the Principality Stadium.
Howley said: "Luke Charteris at this moment is continuing his rehab with the medics. A decision will be made later on in the week.
"Jon Davies will train with us later and we'll see how he is. We're disappointed to lose Cory Allen with an ankle injury. He's due to have an X-ray this afternoon.
"Jon has to get through this afternoon's session. He's an experienced Lions player. It's a difficult time and you're hoping the players who do get released don't get injured. We've run George at 13 in training just in case. It's one of our options.
"Rhys Priestland trained this morning, it was a slight dead leg. It was non-contact and hopefully he'll train this afternoon."